Team Approach: Hip Preservation Surgery.

The evaluation and treatment of adolescents and young adults with hip pain has seen tremendous growth over the past 20 years. Labral tears are well established as a common cause of hip pain but often occur because of underlying bony abnormalities. Femoroacetabular impingement (FAI) and acetabular dysplasia are now well-established causes of hip osteoarthritis and are increasingly treated in the prearthritic stage in hopes of improving symptoms and prolonging the longevity of the native hip. Beyond FAI and acetabular dysplasia, this patient population can present with a complex and variable group of underlying conditions that need to be taken into account. Expertise in the conservative management of this population, including physical therapy, is valuable to maximize the success. Preoperative, surgical, and postoperative decision-making and care in this population is complex and evolving. A comprehensive, multidisciplinary approach to the care of this patient population has been used for over 20 years by our institution with great success. The purpose of this article is to review the "team-based approach" necessary for successful management of the spectrum of adolescent and young adult hip disorders.

Predicting Rates of Angular Correction After Hemiepiphysiodesis in Patients With X-Linked Hypophosphatemic Rickets.

PURPOSE: Patients with X-linked hypophosphatemic rickets (XLH) often develop coronal plane knee deformities despite medical treatment. Hemiepiphysiodesis is an effective way to correct coronal plane knee deformities in skeletally immature patients, but a full understanding of the rate of angular correction after hemiepiphysiodesis in XLH patients, compared with idiopathic cases is lacking. METHODS: We retrospectively reviewed charts of 24 XLH patients and 37 control patients without metabolic bone disease who underwent hemiepiphysiodesis. All patients were treated with standard-of-care medical therapy (SOC=active vitamin D and phosphate salt supplementation) in our clinical research center and had a minimum of 2-year follow-up after hemiepiphysiodesis. Demographic data as well as complications, repeat procedures, or recurrence/overcorrection were recorded. Standing lower extremity radiographs were evaluated before the surgical intervention and at subsequent hardware removal or skeletal maturity, whichever came first. Mean axis deviation, knee zone, mechanical lateral distal femoral angle (mLDFA), and medial proximal tibial angle were measured on each radiograph. The rate of angular correction was calculated as the change in mLDFA and medial proximal tibial angle over the duration of treatment. RESULTS: The magnitude of the initial deformity of the distal femur was greater in XLH patients as compared with control for varus (XLH mLDFA 97.7 +/- 4.9 vs. Control mLDFA 92.0 +/- 2.0 degrees) and valgus (XLH mLDFA 78.7 +/- 6.2 vs. Controls mLDFA 83.6 +/- 3.2 degrees). The rate of correction was dependent on age. When correcting for age, XLH patients corrected femoral deformity at a 15% to 36% slower rate than control patients for the mLDFA (>3 y growth remaining XLH 0.71 +/- 0.46 vs. control 0.84 +/- 0.27 degrees/month, <3 y growth remaining XLH 0.37 +/- 0.33 vs. control 0.58 +/- 0.41 degrees/month). No significant differences were seen in the rate of proximal tibia correction. XLH patients were less likely to end treatment in zone 1 (55.0% XLH vs. 77.8% control). XLH patients had longer treatment times than controls (19.5 +/- 10.7 vs. 12.6 +/- 7.0 mu, P value <0.001), a higher average number of secondary procedures than controls (1.33 +/- 1.44 vs. 0.62 +/- 0.92 number of procedures), a higher rate of overcorrection than controls (29.2% vs. 5.4%), and a higher rate of subsequent corrective osteotomy than controls (37.5% vs. 8.1%). There was no significant difference in the rate of complications between groups (8.3% vs. 5.4%). CONCLUSIONS: Patients with XLH undergoing hemiepiphysiodesis have a 15% to 36% slower rate of femoral deformity correction that results in longer treatment times, a higher likelihood to undergo more secondary procedures, and a lower likelihood to reach neutral mechanical alignment. SIGNIFICANCE: This study provides important information to guide the timing and treatment of patients with XLH and coronal plane knee deformities. In addition, results from this study can be educational for families and patients with respect to anticipated treatment times, success rates of the procedure, complication rate, and likelihood of needing repeat procedures.

Effect of Length Stability on Complications in the Treatment of Preadolescent Diaphyseal Femur Fractures Treated With Elastic Stable Intramedullary Nailing.

OBJECTIVES: To examine the effectiveness and complication rates in age- and size-appropriate patients with either stable or unstable fracture patterns treated with elastic stable intramedullary nailing (ESIN). DESIGN: Retrospective case series. SETTING: Academic tertiary care children's hospital. PATIENTS/PARTICIPANTS: This was a consecutive series of 106 preadolescent children with femoral shaft fractures. The mean age of the patients was 8.0 years (range, 4.0-16.0 years). INTERVENTION: All children were treated by retrograde ESIN. MAIN OUTCOME MEASURES: Fractures were categorized as either length stable or unstable. Length stability and complications were assessed. A subset of patients with final full-length, standing x-rays was also evaluated. RESULTS: We analyzed 63 stable and 43 length unstable fractures. The mean age and weight of the patients with stable and unstable fractures were similar. There was no difference in complication rates between groups (χ2(1) = 0.00, P = 0.99). There was no difference (t(96.93) = 0.53, P = 0.59) in femoral shaft length change. Leg length discrepancies as assessed by full-length standing radiographs at follow-up were similar (χ2(2) = 1.52, P = 0.47). CONCLUSIONS: Preadolescent children younger than 10 years do not experience increased complications after ESIN of length unstable femur fractures [odds ratio (OR) = 1.68 (0.18-16.87), P = 0.65]. Length unstable femur fractures are not at increased risk of more complications [OR = 0.90 (0.26-2.92), P = 0.87], early femoral shortening [OR = (0.42-2.02), P = 0.85], or leg length discrepancy [OR = (0.13-1.56), P = 0.21] when treated with ESIN. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for complete description of levels of evidence.

Is combined surgical dislocation and proximal femoral osteotomy a safe procedure for correction of complex hip deformities?

Complex deformities of the hip requiring intra-articular and proximal femoral correction are challenging with regard to surgical access and complication risk. Combined surgical dislocation and proximal femoral osteotomy (SD/PFO) is a surgical strategy that provides unrestricted access to the joint with the capability for adjunctive PFO. Although providing excellent surgical access, concerns over a potentially high risk of postoperative complications remain, and published information on the safety of this technique remain scarce. In this study, we defined the early complication profile of combined surgery across 48 hips with a variety of complex deformities using a standardized, validated complication grading scheme for hip preservation surgery. Patients were mean age 19.1 years 13-33 years and 60% had previous surgery. At the early mean follow-up of 2.9 years, considerable improvement was seen across all outcome scores. Major complications (Grade III or higher) occurred at a rate of 4.2% (n = 2). Both were osteotomy non-unions, and both were treated successfully with revision PFO and bone grafting at mean 1.1 years. To our knowledge, the current series of combined SD-PFO surgeries represents the largest to date for which detailed complication data have been reported. Given the complexity of these disorders, a major complication rate of 4.2% is acceptable. Our complication rates were comparable to those reported for isolated SD and PFO procedures. These rates did not vary significantly across morphologic variants or patient-specific characteristics. Additionally, our complication risk profile is consistent with previous, smaller reports, which supports the generalizability of these results among appropriately experienced surgeons.

Combined Surgical Dislocation and Periacetabular Osteotomy for Complex Residual Legg-Calvé-Perthes Deformities: Intermediate-Term Outcomes.

BACKGROUND: Residual Legg-Calvé-Perthes (LCP) deformities represent one of the most challenging disorders in hip reconstructive surgery. In complex cases, both instability (acetabular dysplasia) and multifocal femoroacetabular impingement (FAI) (proximal femoral deformities) require correction. We assessed intermediate-term patient-reported outcome measures, radiographic correction, complications, and survivorship for combined surgical dislocation (SD) and periacetabular osteotomy (PAO) for the treatment of complex LCP deformities. METHODS: A retrospective cohort study was performed on 31 hips with complex LCP deformities undergoing combined SD and PAO for concurrent instability and FAI. Treatment included femoral head reshaping, trochanteric advancement and relative femoral neck lengthening, management of intra-articular lesions, and PAO. Twenty-seven hips (87%) had a minimum follow-up of 5 years. The mean age was 19.8 years, 56% of patients were female, and 44% of patients had undergone a previous surgical procedure. RESULTS: At a mean of 8.4 years, 85% of hips (23 of 27) remained preserved (no conversion to total hip arthroplasty). The survivorship estimates were 93% at 5 years and 85% at 10 years. The median (and interquartile range) increased from 64 points (55, 67 points) to 92 points (70, 97 points) (p < 0.001) for the modified Harris hip score (mHHS) and from 60 points (45, 75 points) to 86 points (75, 100 points) (p = 0.001) for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score. Symptoms (mHHS < 70 points) were reported for an additional 19% of hips (n = 5) at the final follow-up. The University of California Los Angeles (UCLA) activity score increased from a median of 8 points (6, 10 points) to 9 points (7, 10 points) (p = 0.207). Structural correction included mean improvement (and standard deviation) of 15.3° ± 7.6° for acetabular inclination, 20.7° ± 10.8° for the lateral center-edge angle, 23.4° ± 16.3° for the anterior center-edge angle, and 18 ± 10 mm for trochanteric height (p < 0.001 for all). Complications occurred in 2 hips (7%), including 1 deep wound infection and 1 superficial wound infection. There was 1 reoperation due to complication, but there were no nerve palsies, thromboembolic events, fractures, or nonunions. CONCLUSIONS: At an intermediate follow-up of combined SD and PAO for complex LCP deformities, 85% of hips were preserved. This procedure provides reliable deformity correction, major pain relief, improved function, and acceptable complication and failure rates. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Severe Hip Dysplasia in Skeletally Mature Patients With Spastic Cerebral Palsy: The Technique and Early Outcome of Comprehensive Surgical Correction (Including the Bernese PAO).

BACKGROUND: Treatment of symptomatic hip dysplasia in skeletally mature patients with spastic cerebral palsy (CP) can be challenging. This study examines our technical experience with the Bernese periacetabular osteotomy (PAO) in combination with adjunctive procedures in the treatment of this complex hip deformity. METHODS: Sixteen consecutive patients (18 hips) with symptomatic CP hip dysplasia were treated with a PAO and variable adjunctive procedures and retrospectively reviewed. Two patient (2 hips) were excluded due to insufficient follow-up. The average age at the time of surgery was 17.7 years (range: 13 to 28 y). We compared the preoperative to postoperative changes in radiographic parameters as well as early outcomes as measured by patient assessment of hip pain and function using the modified Harris Hip Score (mHHS). RESULTS: The average time of follow-up was 3.3 years (range: 2.0 to 6.3 y). Tönnis angles decreased from a median of 30 degrees (range: 18 to 45 degrees) preoperatively to a median of 6 degrees (range: -9 to 21 degrees) postoperatively. Lateral center-edge angles increased from a median of -8 degrees (range: -28 to 15 degrees) to a median of 32 degrees (range: 19 to 38 degrees). Anterior center-edge angles increased from a median of 2 degrees (range: -22 to 39 degrees) to a median of 35 degrees (range: 22 to 47 degrees). The extrusion index decreased from a median of 57% preoperatively (range: 35% to 73%) to a median of 21% (range: 11% to 36%) postoperatively.The median mHHS was 62 (range: 37 to 81) preoperatively and 85 (range: 65 to 100) postoperatively. Notably, the pain component of the mHHS improved from 20 (range: 0 to 44) to 42 (range: 30 to 44). Tönnis osteoarthritis grade preoperatively was either 0 (11 hips) or 1 (5 hips) and remained unchanged in 11 hips and increased by 1 grade in 5 hips. CONCLUSIONS: It has been our experience that the Bernese PAO in combination with appropriate adjunctive treatments has provided a very satisfactory surgical approach in the treatment of CP hip dysplasia. In the adolescent and young adult with spastic CP, utilizing the Bernese PAO technique makes it possible to obtain redirection of often a very severe acetabular dysplasia. Adjunctive soft tissue procedures and a proximal femoral osteotomy are frequently necessary to maintain postoperative stability. A notable improvement in the quality of life and function directly attributable to our surgical treatment of their pre-existing problematic hip dysplasia has been consistently noted in early follow-up for our patients. LEVEL OF EVIDENCE: Level IV-therapeutic.

Limb lengthening in the treatment of posteromedial bowing of the tibia.

PURPOSE: Posteromedial bowing of the tibia is an uncommon but recognized congenital lower extremity deformity in children that can lead to limb length discrepancy (LLD) and residual angulatory deformity. The purpose of this study is to report a series of children at a single institution with posteromedial bowing treated by lengthening. METHODS: A retrospective review was carried out at our institution identifying 16 patients who were treated with limb lengthening for posteromedial bowing of the tibia and followed to skeletal maturity. Projected LLD was a mean of 7.7 cm (range 5.0 cm to 14.2 cm). Three patients were treated in a staged fashion with lengthening and deformity correction at age three to four years and subsequent definitive tibial lengthening. The remaining 13 patients were treated with limb lengthening approaching adolescence using circular external fixation. RESULTS: All patients were pain free and ambulated without a limp at final follow-up. The mean final LLD was 0.3 cm short. In spite of correction of distal tibial shaft valgus in 11 of the 16 patients, eight of the 16 (50%) required later correction of persistent, symptomatic ankle valgus by either hemiepiphyseodesis (seven patients) or osteotomy (one patient). CONCLUSIONS: Children with posteromedial bowing of the tibial with projected LLD over 5cm can be effectively treated with lengthening. Patients with severe valgus of more than 30° of shaft valgus and difficulty ambulating at age three years can be successfully treated with a two-stage lengthening procedure. Attention should be paid in patients with posteromedial bowing to ankle valgus. LEVEL OF EVIDENCE: IV.

Treatment of femoral fractures in children aged two to six.

AIMS: Current American Academy of Orthopaedic Surgeons (AAOS) guidelines for treating femoral fractures in children aged two to six years recommend early spica casting although some individuals have recommended intramedullary stabilization in this age group. The purpose of this study was to compare the treatment and family burden of care of spica casting and flexible intramedullary nailing in this age group. METHODS: Patients aged two to six years old with acute, non-pathological femur fractures were prospectively enrolled at one of three tertiary children's hospitals. Either early closed reduction with spica cast application or flexible intramedullary nailing was accomplished under general anaesthesia. The treatment method was selected after discussion of the options by the surgeon with the family. Data were prospectively collected on patient demographics, fracture characteristics, complications, pain medication, and union. The Impact on Family Scale was obtained at the six-week follow-up visit. In all, 75 patients were included in the study: 39 in the spica group and 36 in the nailing group. The mean age of the spica group was 2.71 (2.0 to 6.9) years and the mean age of the nailing group was 3.16 (2.0 to 6.9) years. RESULTS: All fractures healed without evidence of malunion or more than 2.0 cm of shortening. The mean Impact on Family score was 70.2 for the spica group and 63.2 (55 to 99) for the nailing group, a statistically significant difference (p = 0.024) in a univariate analysis suggesting less impairment of the family in the intramedullary nailing group. There was no significant difference between pain medication requirements in the first 24 hours postoperatively. Two patients in the spica group and one patient in the intramedullary nailing group required additional treatment under anaesthesia. CONCLUSION: Both early spica casting and intramedullary nailing were effective methods for treating femoral fractures in children two to six years of age. Intramedullary stabilization provides an option in this age group that may be advantageous in some social situations that depend on the child's mobility. Fracture treatment should be individualized based on factors that extend beyond anatomical and biological factors. Cite this article: Bone Joint J 2020;102-B(8):1056-1061.

Open Reduction and Internal Fixation for the Treatment of Symptomatic Osteochondritis Dissecans of the Femoral Head in Patients With Sequelae of Legg-Calvé-Perthes Disease.

BACKGROUND: Osteochondritis dissecans (OCD) is estimated to occur in 2% to 7% of patients with Legg-Calvé-Perthes disease (LCPD). Unstable osteochondral fragments secondary to LCPD may produce mechanical symptoms requiring surgical intervention. Reattachment of the fragment with open reduction and internal fixation (ORIF) may provide good clinical outcomes. The purpose of this study is to report short-term clinical and radiographic results of ORIF for the treatment of symptomatic osteochondral lesions resulting from LCPD. METHODS: Clinical data including patient demographics and patient-reported outcome scores were collected prospectively. All patients underwent preoperative radiographs and magnetic resonance imaging confirming an unstable OCD fragment as well as postoperative radiographs at regular intervals. Indications for ORIF of the OCD fragment were hip pain and mechanical symptoms with radiographic evidence of LCPD and a magnetic resonance imaging demonstrating an OCD fragment of the femoral head. Osteochondral fragment instability was confirmed intraoperatively. Preoperative and postoperative physical examination findings were documented. All patients failed a course of nonsurgical treatment (activity modification, anti-inflammatories, and physical therapy). RESULTS: From a total of 64 consecutive patients treated with hip preservation surgery for LCPD, 7 patients with symptomatic OCD secondary to LCPD were treated with surgical hip dislocation and ORIF of the femoral head osteochondral fragment. OCD size lesion ranged from 200 to 625 mm. All patients reported marked clinical improvement, with resolution of both pain and mechanical symptoms. Radiographs at final follow-up demonstrated complete osteochondral fragment healing without implant failure. Mean follow-up was 4.6 years (range, 1.1 to 7.4 y). There was a significant postoperative improvement in measured internal rotation in flexion (5.0±5.0 to 16.4±9.8; P=0.02). Modified Harris Hip Score markedly improved from baseline to final follow-up (47.8 to 82.7; [INCREMENT]34.9; minimal clinically important difference, 11; P=0.002), with all patients meeting minimal clinically important difference for modified Harris Hip Score. There were no complications and no progression of osteoarthritis in all patients at final follow-up. CONCLUSIONS: We have demonstrated both predictable radiographic healing and marked clinical improvement following ORIF of symptomatic post-Perthes OCD lesions. We advocate ORIF for symptomatic osteochondral lesions as a first-line surgical treatment for these patients due to the advantages of native osteochondral tissue preservation, predictable healing, and marked clinical improvement. LEVEL OF EVIDENCE: Level IV-case series.

Late Effects of Clubfoot Deformity in Adolescent and Young Adult Patients Whose Initial Treatment Was an Extensive Soft-tissue Release: Topic Review and Clinical Case Series.

Children with congenital clubfoot often have residual deformity, pain, and limited function in adolescence and young adulthood. These patients represent a heterogeneous group that often requires an individualized management strategy. This article reviews the available literature on this topic while proposing a descriptive classification system based on a review of patients at our institution who underwent surgery for problems related to previous clubfoot deformity during the period between January 1999 and January 2012. Seventy-two patients (93 feet) underwent surgical treatment for the late effects of clubfoot deformity at an average age of 13 years (range 9 to 19 years). All patients had been treated at a young age with serial casting, and most had at least one previous surgery on the affected foot or feet. Five common patterns of pathology identified were as follows: undercorrection, overcorrection, dorsal bunion, anterior ankle impingement, and lateral hindfoot impingement. Management pathways for each group of the presenting problems is described. To our knowledge, this topic review represents the largest report of adolescent and young adult patients with residual clubfoot deformity in the literature.

Activity Level Maintenance at Midterm Follow-up Among Active Patients Undergoing Periacetabular Osteotomy.

BACKGROUND: For active patients undergoing periacetabular osteotomy (PAO), returning to and maintaining a high level of activity postoperatively is a priority. PURPOSE: To evaluate the maintenance of activity levels at midterm follow-up in active patients treated with PAO for symptomatic acetabular dysplasia. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients who underwent PAO for symptomatic acetabular dysplasia between June 2006 and August 2013 were identified by a retrospective review of our prospective longitudinal institutional Hip Preservation Database. All patients with a preoperative University of California, Los Angeles (UCLA) score of ≥7 and a potential minimum 5 years of follow-up were included in the study. Functional outcome measures were the UCLA score, modified Harris Hip Score (mHHS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). The maintenance of high activity levels was defined as a UCLA score of ≥7 at final follow-up. Radiographic parameters were measured. Statistical significance was defined as a P value <.05. RESULTS: A total of 66 hips (58 patients) were included. The mean age was 25.3 years (range, 14-47 years), the mean body mass index was 23.9 kg/m2 (range, 19-32 kg/m2), and 72% were female. The mean follow-up was 6.8 years (range, 5-11 years). There were 67% of patients who maintained a UCLA score of ≥7. Patient-reported outcomes improved postoperatively from preoperatively for the mHHS (88 ± 14 vs 67 ± 17, respectively; P < .001) and WOMAC (89 ± 15 vs 73 ± 20, respectively; P < .001). The lateral center-edge angle, anterior center-edge angle, and acetabular inclination were significantly improved at final follow-up (P < .001). Only 4 patients (7%) cited postoperative activity limitations as being caused by hip pain. There were no conversions to total hip arthroplasty. CONCLUSION: The majority (67%) of active patients returned to preoperative or higher activity levels after PAO at midterm follow-up.

Complications associated with combined surgical hip dislocation and periacetabular osteotomy for complex hip deformities.

Surgical hip dislocation (SD) and periacetabular osteotomy (PAO) are well-described treatments for femoroacetabular impingement (FAI) and acetabular dysplasia, respectively. Occasionally, complex deformities require a combined SD/PAO; the morbidity of performing both procedures in a single stage has not been fully investigated. We performed a retrospective review of a consecutive group of patients undergoing combined SD/PAO to investigate the incidence and character of perioperative complications. Forty-five patients (46 hips) were identified. Perioperative complications were graded by the modified Clindo-Davien complication scheme. Mean follow-up was 36 months (range 12-128), and no patients were lost to follow-up. Six complications occurred in six hips (13%). Four (8.7%) complications were minor (Grades I or II): one Brooker Grade III heterotopic ossification requiring no treatment, one superior pubic ramus nonunion requiring no treatment and two superficial wound infections requiring antibiotics. Two (4.3%) complications were major (Grades III or IV): one coxa saltans interna and labral tear requiring hip arthroscopy with labral repair and iliopsoas lengthening, and one deep surgical site infection requiring irrigation and debridement followed by development of arthritis requiring conversion to arthroplasty. The average Harris hip score improved from 62 ± 13 preoperatively to 80 ± 19 at final follow-up. Except for the single joint replacement, there were no long-term disabilities. There were no major neurovascular injuries, osteonecrosis, fractures or trochanteric nonunions. Combined SD/PAO for the treatment of complex, concomitant deformities of the proximal femur and acetabulum is associated with an acceptable risk of complications. The vast majority of complications that occurred were managed without permanent disability. Level of Evidence: IV.

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.

Development of the HOOSglobal to Assess Patient-Reported Outcomes in Patients Undergoing Hip Preservation Procedures.

BACKGROUND: The creation of a single patient-reported outcome (PRO) platform validated across hip preservation, osteoarthritis (OA), and total hip arthroplasty (THA) populations may reduce barriers and streamline the routine collection of PROs in clinical practice. As such, the purpose of this study was to determine if augmenting the Hip disability and Osteoarthritis Outcome Score-Joint Replacement (HOOS, JR) with additional HOOS questions would result in a PRO platform that could be used across a wider spectrum of hip patient populations. HYPOTHESIS: The HOOS, JR would demonstrate a notable ceiling effect, but by augmenting the HOOS, JR with additional HOOS questions, a responsive PRO platform could be created. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Using preoperative and postoperative HOOS responses from a sample of 304 patients undergoing periacetabular osteotomy (PAO), additional items were identified to augment the HOOS, JR. The psychometric properties of a newly created PRO tool (HOOSglobal) were then compared with the HOOS, JR and other PRO instruments developed for patients with hip OA and/or undergoing THA. RESULTS: By augmenting the HOOS, JR with 2 additional questions, the HOOSglobal was more responsive than all other included PRO tools and had significantly fewer maximum postoperative scores than the HOOS, JR ( P < .0001), HOOS-Physical Function Short form ( P < .0001), Western Ontario and McMaster Universities Osteoarthritis Index ( P = .02), University of California, Los Angeles activity scale ( P = .0002), and modified Harris Hip Score ( P = .04). The postoperative HOOSglobal score threshold associated with patients achieving the patient acceptable symptom state (PASS) was 62.5. CONCLUSION: The HOOSglobal is a valid and responsive PRO tool after PAO and may potentially provide the orthopaedic community with a PRO platform to be used across hip-related subspecialties. For patients undergoing PAO, a postoperative HOOSglobal score ≥62.5 was associated with patients achieving the PASS.

Knee Pain and Activity Outcomes After Femoral Derotation Osteotomy for Excessive Femoral Anteversion.

BACKGROUND: Excessive femoral anteversion is a developmental condition that can become symptomatic into adolescence and manifest as anterior knee pain, tripping, and or problems with sports. Femoral derotational osteotomy about an antegrade intramedullary nail (IMN) is an accepted option to treat this condition. This is the first report of the clinical and functional outcomes of treatment of excessive anteversion with femoral derotational osteotomy stabilized with an IMN. METHODS: We prospectively enrolled 28 consecutive patients between 2013 and 2014 who underwent derotational osteotomy. Physical examination measures were used to calculate the amount of angular correction with focus on internal and external rotation of the hip, as well as the trochanteric prominence angle test of femoral anteversion. The International Knee Documentation Committee-9, Marx, and Tegner activity scales were 3 patient-reported outcomes recorded. RESULTS: After femoral derotation osteotomy over an IMN, femoral anteversion, as measured by the trochanteric prominence angle, improved an average of 29 degrees (P<0.0001). At 1-year minimum follow-up, 22 of 28 subjects (78.5%) demonstrated a mean significant improvement of 13 points for International Knee Documentation Committee-9 (SD=15.4, P=0.0007), which surpassed the level of minimal clinically important change. Furthermore, the Tegner inventory scores for the cohort improved by an average of 1.9 activity levels (SD=2.4, P=0.0012). CONCLUSIONS: For adolescents with symptomatic excessive femoral anteversion, derotational osteotomy over an IMN offers a reliable surgical option that provides predictable deformity correction and significant improvements in both function and pain scales. LEVELS OF EVIDENCE: Level II-prospective, consecutive, nonrandomized, internally controlled cohort study.

Descriptive Epidemiology of Acetabular Dysplasia: The Academic Network of Conservational Hip Outcomes Research (ANCHOR) Periacetabular Osteotomy.

BACKGROUND: Periacetabular osteotomy (PAO) is an established treatment for symptomatic acetabular dysplasia, which is a well-recognized cause of hip pain, functional limitations, and secondary osteoarthritis. The purpose of this study was to describe the demographics of patients undergoing PAO, the baseline patient-reported outcome measures for this population, and the types of adjunctive procedures performed at the time of PAO surgery. METHODS: Demographics, disease characteristics, and patient-reported functional measures were prospectively collected from all patients who underwent PAO performed by 12 surgeons from 2008 to 2013. RESULTS: We enrolled 950 consecutive patients (982 hips) in the study; 83% were female and 17% were male, with an average age of 25.3 years and an average body mass index (BMI) of 24.6 kg/m. Most patients were Caucasian (87%), and 15% had undergone previous hip surgery. Before PAO was performed, most patients had had symptoms for 1 to 3 years. Baseline modified Harris Hip and University of California Los Angeles activity scores (61.8 and 6.6, respectively) indicated that patients had considerable functional limitations. DISCUSSION: Patients undergoing PAO for symptomatic dysplasia were predominantly young, female, and Caucasian with a normal BMI. Many patients had undergone prior hip surgery, and most had had symptoms for several years before treatment. Baseline patient-reported functional scores demonstrated marked functional limitations. Adjunctive procedures for intra-articular pathology, especially femoral osteochondroplasty and hip arthroscopy, are commonly performed at the time of PAO.

Patient-Reported Outcomes of Periacetabular Osteotomy from the Prospective ANCHOR Cohort Study.

BACKGROUND: Current literature describing the periacetabular osteotomy (PAO) is mostly limited to retrospective case series. Larger, prospective cohort studies are needed to provide better clinical evidence regarding this procedure. The goals of the current study were to (1) report minimum 2-year patient-reported outcomes (pain, hip function, activity, overall health, and quality of life), (2) investigate preoperative clinical and disease characteristics as predictors of clinical outcomes, and (3) report the rate of early failures and reoperations in patients undergoing contemporary PAO surgery. METHODS: A large, prospective, multicenter cohort of PAO procedures was established, and outcomes at a minimum of 2 years were analyzed. A total of 391 hips were included for analysis (79% of the patients were female, and the average patient age was 25.4 years). Patient-reported outcomes, conversion to total hip replacement, reoperations, and major complications were documented. Variables with a p value of ≤0.10 in the univariate linear regressions were included in the multivariate linear regression. The backward stepwise selection method was used to determine the final risk factors of clinical outcomes. RESULTS: Clinical outcome analysis demonstrated major clinically important improvements in pain, function, quality of life, overall health, and activity level. Increasing age and a body mass index status of overweight or obese were predictive of improved results for certain outcome metrics. Male sex and mild acetabular dysplasia were predictive of lesser improvements in certain outcome measures. Three (0.8%) of the hips underwent early conversion to total hip arthroplasty, 12 (3%) required reoperation, and 26 (7%) experienced a major complication. CONCLUSIONS: This large, prospective cohort study demonstrated the clinical success of contemporary PAO surgery for the treatment of symptomatic acetabular dysplasia. Patient and disease characteristics demonstrated predictive value that should be considered in surgical decision-making. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Do Radiographic Parameters of Dysplasia Improve to Normal Ranges After Bernese Periacetabular Osteotomy?

BACKGROUND: The goal of periacetabular osteotomy (PAO) is to improve the insufficient coverage of the femoral head and achieve joint stability without creating secondary femoroacetabular impingement. However, the complex tridimensional morphology of the dysplastic acetabulum presents a challenge to restoration of normal radiographic parameters. Accurate acetabular correction is important to achieve long-term function and pain improvement. There are limited data about the proportion of patients who have normal radiographic parameters restored after PAO and the factors associated with under- and overcorrection. QUESTIONS/PURPOSES: (1) What is the proportion of patients undergoing PAO in which the acetabular correction as assessed by the lateral center-edge angle (LCEA), anterior center-edge angle (ACEA), acetabular inclination (AI), and extrusion index (EI) is within defined target ranges? (2) What patient and preoperative factors are associated with undercorrection of the acetabulum as defined by a LCEA < 22°, a factor that has been reported to be associated with PAO failure at 10-year followup? METHODS: Between January 2007 and December 2011 we performed 132 PAOs in 116 patients for treatment of symptomatic acetabular dysplasia. One patient with Legg-Calvé-Perthes disease, one with multiple osteochondromatosis, and two with concomitant femoral osteotomy were excluded. A total of 128 hips (112 patients) were included. The hip cohort was 76% (97 of 128) female and the mean age at surgery was 28.5 years (SD 8.7 years). Correction of LCEA between 25° and 40°, ACEA between 18° and 38°, Tönnis angle between 0° and 10°, and EI ≤ 20% were defined as adequate based on normative values. Values lower than the established parameters were considered undercorrection for the LCEA and ACEA and those higher than the established values were considered overcorrection. Because postoperative LCEA < 22o has been previously associated with PAO failure at a minimum of 10-year followup, in this study we sought to measure whether demographic factors including age, gender, body mass index, and severity of acetabular dysplasia assessed by preoperative LCEA, ACEA, AI, and EI were associated with undercorrection. Postoperative radiographs were obtained at minimum of 1 month after surgery (mean, 7 months; range, 1-44 months) and were measured by a professional research assistant and a hip reconstruction fellow not involved in the clinical care of the patients. No patient was lost to followup. RESULTS: Of the 128 hips, the proportion of hips with radiographic parameters within the established range was 78% (100 hips) for the LCEA, 86% (110 hips) for the ACEA, 89% (114 hips) for the AI, and 80% (102 hips) for the EI. For hips with an inadequate correction, the LCEA was more often undercorrected than overcorrected (20% versus 2%; 95% confidence interval [CI], 11%-27%; p < 0.001), whereas the ACEA was more often overcorrected than undercorrected (11% versus 3%; 95% CI, 1%-15%; p = 0.03) After adjusting for age, sex, body mass index, and preoperative radiographic parameters including ACEA, AI, and EI, we found that the preoperative LCEA was the only independent factor associated with a postoperative LCEA < 22° (odds ratio, 0.92; 95% CI, 0.87-0.97; p = 0.003), indicating that hips with lower preoperative LCEA were more likely to have a LCEA < 22°. For each additional degree of preoperative LCEA, the odds of LCEA < 22° were reduced by 15%. CONCLUSIONS: Acetabular correction after PAO performed by two experienced surgeons was adequate for individual radiographic parameters in most but not all hips. Hips with more severe dysplasia preoperatively are at higher risk for undercorrection as assessed by the LCEA. This intuitive information may help surgeons performing PAO in severely dysplastic hips plan for possible combined procedures including a femoral osteotomy if PAO alone does not allow for adequate correction of femoral head coverage and a congruous concentric hip. Further studies are planned to determine whether the long-term hip function and pain in patients whose hips were corrected within these established parameters will be improved in comparison to those that were under- or overcorrected. LEVEL OF EVIDENCE: Level III, therapeutic study.

Three Patterns of Acetabular Deficiency Are Common in Young Adult Patients With Acetabular Dysplasia.

BACKGROUND: Detailed recognition of the three-dimensional (3-D) deformity in acetabular dysplasia is important to help guide correction at the time of reorientation during periacetabular osteotomy (PAO). Common plain radiographic parameters of acetabular dysplasia are limited in their ability to characterize acetabular deficiency precisely. The 3-D characterization of such deficiencies with low-dose CT may allow for more precise characterization. QUESTIONS/PURPOSES: The purposes of this study were (1) to determine the variability in 3-D acetabular deficiency in acetabular dysplasia; (2) to define subtypes of acetabular dysplasia based on 3-D morphology; (3) to determine the correlation of plain radiographic parameters with 3-D morphology; and (4) to determine the association of acetabular dysplasia subtype with patient clinical characteristics including sex, range of motion, and femoral version. METHODS: Using our hip preservation database, we identified 153 hips (148 patients) that underwent PAO from October 2013 to July 2015. Among those, we noted 103 hips in 100 patients with acetabular dysplasia (lateral center-edge angle < 20°) and who had a Tönnis grade of 0 or 1. Eighty-six patients (86%) underwent preoperative low-dose pelvic CT scans at our institution as part of the preoperative planning for PAO. It is currently our standard to obtain preoperative low-dose pelvic CT scans (0.75-1.25 mSv, equivalent to three to five AP pelvis radiographs) on all patients before undergoing PAO unless a prior CT scan was performed at an outside institution. Hips with a history of a neuromuscular disorder, prior trauma, prior surgery, radiographic evidence of joint degeneration, ischemic necrosis, or Perthes-like deformities were excluded. Fifty hips in 50 patients met inclusion criteria and had CT scans available for review. These low-dose CT scans of 50 patients with symptomatic acetabular dysplasia undergoing evaluation for surgical planning of PAO were then retrospectively studied. CT scans were analyzed quantitatively for acetabular coverage, relative to established normative data for acetabular coverage, as well as measurement of femoral version. The cohort included 45 females and five males with a mean age of 26 years (range, 13-49 years). RESULTS: Lateral acetabular deficiency was present in all patients, whereas anterior deficiency and posterior deficiency were variable. Three patterns of acetabular deficiency were common: anterosuperior deficiency (15 of 50 [30%]), global deficiency (18 of 50 [36%]), and posterosuperior deficiency (17 of 50 [34%]). The presence of a crossover sign or posterior wall sign was poorly predictive of the dysplasia subtype. With the numbers available, males appeared more likely to have a posterosuperior deficiency pattern (four of five [80%]) compared with females (13 of 45 [29%], p = 0.040). Hip internal rotation in flexion was significantly greater in anterosuperior deficiency (23° versus 18°, p = 0.05), whereas external rotation in flexion was significantly greater in posterosuperior deficiency (43° versus 34°, p = 0.018). Acetabular deficiency pattern did not correlate with femoral version, which was variable across all subtypes. CONCLUSIONS: Three patterns of acetabular deficiency commonly occur among young adult patients with mild, moderate, and severe acetabular dysplasia. These patterns include anterosuperior, global, and posterosuperior deficiency and are variably observed independent of femoral version. Recognition of these distinct morphologic subtypes is important for diagnostic and surgical treatment considerations in patients with acetabular dysplasia to optimize acetabular correction and avoid femoroacetabular impingement.

Femoral Deformity May Be More Predictive of Hip Range of Motion Than Severity of Acetabular Disease in Patients With Acetabular Dysplasia: An Analysis of the ANCHOR Cohort.

BACKGROUND: It is generally believed that acetabular dysplasia (AD) is associated with increased hip range of motion (ROM). The purpose of this study was to investigate the associations between dysplasia severity and hip ROM in a large multicenter cohort. METHODS: A prospective registry of patients undergoing periacetabular osteotomy for symptomatic AD by 1 of 13 surgeons was used to analyze 1,051 patients (mean age, 26 ± 10 years). Multivariable linear regression modeling was used to investigate for associations between dysplasia severity (severe, <5°; moderate, 5° to 15°; mild, >15°), α angle, and hip ROM. RESULTS: When controlling for age, sex, body mass index, and α angle, only internal (α = 1.94; P = 0.005) and external (α = -2.63; P < 0.001) rotation in extension were significantly different between groups with increasing dysplasia severity. Alpha angle was greater for those with severe AD compared with subjects with mild disease (60° ± 16° versus 57° ± 15°; P = 0.038). Alpha angle was also significantly correlated with rotational ROM parameters (internal and external rotation in flexion and extension) (Pearson r, range: -0.077 to -0.216; P < 0.05 for all), but not with linear motion. CONCLUSIONS: Internal rotation in extension was directly associated with dysplasia severity, whereas external rotation in extension was inversely associated. Furthermore, α angle was greater with increasing dysplasia severity and predictive of rotational ROM parameters. Taken together, these data suggest that femoral-sided deformity, including α angle and possibly femoral version, may be responsible for differences in ROM based on dysplasia severity. LEVEL OF EVIDENCE: Level III, Prognostic.