Sierra, Rafael J

ABSTRACT Femoroacetabular impingement (FAI) of the hip results from altered morphology of the proximal femur and/or acetabulum, creating abnormal contact between these structures during normal hip range of motion. The etiology of this structural phenotype is unknown. This study aimed to identify common single‐nucleotide variants (SNVs) among two families with seemingly heritable FAI. Additionally, this study examined biologic networks among proteins encoded by identified SNVs and surveyed the literature regarding the role of these proteins in musculoskeletal development. Methodologically, blood samples were collected from affected and unaffected members of two separate families with a pattern of heritable FAI. Exome sequencing identified SNVs, and a protein–protein interaction network assessment, in addition to a literature review, was performed to better understand the role of variant‐associated genes in musculoskeletal development. Results showed 33 and 43 variant‐associated genes affected in Family 1 and Family 2, respectively. Although no overlap in variant‐associated genes was found between families, network analysis showed that variant‐associated genes are functionally interconnected and are known to interact with each other. Furthermore, the variant‐associated genes are broadly associated with musculoskeletal development. Ultimately, genetic analysis of two families of multiple generations of FAI revealed variations in genes regulating musculoskeletal development, with several being critical local regulators of bone morphogenesis.

Abstract The Guardian table is widely utilized for combined hip arthroscopy and periacetabular osteotomy (PAO) due to its postless traction design and the ability to perform both procedures without the need for redraping. This retrospective cohort study reports one surgeon’s use of the Guardian table extension during combined hip arthroscopy and PAO and the occurrence of intraoperative posterior column fractures. Seventy-two consecutive PAO procedures performed at a single institution between February 2023 and January 2025 were analysed. Procedures involving concomitant hip arthroscopy (n = 26) utilized the Guardian table, whereas those without arthroscopy (n = 46) used a conventional radiolucent table. Patient demographics, clinical data, and complications were reviewed. Additionally, mechanical testing quantified table stability by measuring peak absolute acceleration (‘table bounce’) using accelerometry during simulated malleting. The incidence of intraoperative posterior column fractures was significantly higher with the Guardian table (4/26, 15.4%) compared to the conventional table (0/46, 0%; P = .0062). Mechanical testing demonstrated significantly greater table bounce for the Guardian table (69.1 ± 3.4 m/s2 versus 28.2 ± 4.4 m/s2, P < .001). Patient characteristics and surgical complexity did not differ significantly between fracture and non-fracture cases. These findings suggested that the Guardian table extension system was associated with increased risk of posterior column fractures, likely due to lack of distal support and stability. Surgeons should consider alternative table setups or intraoperative support modifications to mitigate this risk during PAO procedures.

Abstract The acetabular labrum is a fibrocartilaginous structure that deepens the acetabular socket and helps maintain a suction seal. In patients with hip dysplasia, a distinct labral tear pattern called an inside‐out labral tear is often seen. This tear pattern is particularly challenging to correct via conventional techniques since the labrum can potentially remain everted and insufficiently restore the native hip labral suction seal after repair. An inverted hip labral repair technique is performed for this pathology at our institution and focuses on achieving optimal labral orientation to enhance the suction seal and joint stability, particularly in dysplastic hips. This Technical Note aims to describe the key surgical principles and clinical considerations of inverted hip labral repair. Technique Video video See video under supplementary data.

Background: An extended trochanteric osteotomy (ETO) is commonly used to improve exposure and facilitate femoral component removal in revision total hip arthroplasty (THA). An additional medial corticotomy may be used in conjunction with an ETO to correct a femoral deformity, particularly varus remodeling in association with a failed femoral component. This study evaluated the outcomes of combining an ETO with a medial corticotomy in revision THA, with emphasis on implant fixation, femoral alignment, bone union, and clinical outcomes. Methods: Of the 612 ETOs performed between 2003 and 2013, 13 patients (9 men and 4 women) underwent ETO combined with a medial corticotomy to correct varus remodeling, representing 2% of all ETOs during that period. The average follow-up was 8 ± 3.5 years. The mean age at surgery was 67 ± 13.5 years. The mean body mass index was 32 ± 7.7 kg/m 2 . Radiographs were reviewed to measure preoperative and postoperative femoral deformity, time to consolidation, and femoral fixation. Clinical outcomes were evaluated using the Harris Hip Score (HHS). Results: All patients had preoperative varus femoral deformity (mean 16.3° ± 5.7°). The mean postoperative alignment was 4.3 ± 1.6° varus achieving an average correction of 12° (95% CI −15.7 to −8.3, p < 0.0001). Both the ETO and the medial corticotomy consolidated in 10 of 11 patients (91%) with available 1-year radiographs at a mean of 11 ± 7.7 months. The mean HHS improved significantly from 42 preoperatively to 82 at 5-year follow-up (p = 0.0002). Complications related to the ETO and corticotomy occurred in 4 patients (30%), including 1 intraoperative fracture, 1 postoperative greater trochanteric fracture, 1 nonunion of the medial corticotomy, and 1 postoperative wound-hematoma. All femoral components remained well fixed at final follow-up. Conclusion: The combination of ETO and medial corticotomy in revision THA effectively corrected femoral alignment in patients with a preoperative varus deformity and was associated with significant functional improvement at the final follow-up. Level of Evidence: Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: Gluteus medius tears and atrophy cause lateral hip pain, limp, and functional impairment. We developed the “broken wing sign,” a novel physical examination test for detecting gluteus medius tendon tears and muscle degeneration. This study evaluated its diagnostic accuracy and clinical utility against magnetic resonance imaging (MRI) and intraoperative findings. Methods: We prospectively examined 59 patients (75 hips; mean age, 69.5 ± 10.8 years; 48 women) with suspected hip abductor insufficiency. The broken wing sign was tested with patients prone, the knee flexed at 90°, and the hip actively extended. A positive sign involved ≥10° of compensatory external hip rotation, visible as an inward drift of the foot, indicating gluteus medius (and resulting internal rotation) weakness. MRI served as the reference standard for classifying gluteus medius integrity as no tear, partial, full-thickness, or massive. Fatty infiltration was graded (Goutallier grades 0 to 4), quantified, and analyzed for a correlation with the examination findings. Diagnostic accuracy metrics were calculated. Results: The broken wing sign demonstrated high accuracy (sensitivity, 81.8%; specificity, 80.0%; positive predictive value [PPV], 91.8%; negative predictive value, 61.5%; diagnostic odds ratio, 17.8). An external rotation threshold of ≥30° yielded 100% specificity and 100% PPV for a tear. The sign detected acute tears with no or minimal fatty infiltration (100% sensitivity for massive tears). The degree of the external rotation angle was strongly correlated with muscle atrophy with fatty infiltration, showing 88.0% sensitivity for Goutallier grade ≥3 and 100% sensitivity for grade 4. Conclusions: The broken wing sign is clinically useful for diagnosing gluteus medius tendon tears and muscle atrophy, particularly massive tears and advanced fatty degeneration. It effectively guides MRI utilization and surgical planning, serving as a valuable initial diagnostic tool in the clinical setting. Level of Evidence: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Background: Total hip arthroplasty (THA) effectively restores mobility, reduces pain, and enhances the quality of life of patients of all ages. Despite its benefits, concerns regarding the long-term effects of high-impact activities and sports on implant longevity require further study. This study investigated the effect of activity level on long-term radiographic wear of highly cross-linked polyethylene (HXLPE) in young patients undergoing THA. Methods: Between 1999 and 2008, 785 patients (909 hips) aged ≤50 underwent primary THA using first-generation HXLPE liners from 4 different vendors with either metal or ceramic heads. Functional activity and participation questionnaires, including the Hip Injury and Osteoarthritis Outcome Score (HOOS Jr), University of California Los Angeles (UCLA) activity scale, and High-Activity Arthroplasty Score (HAAS), were surveyed in 2018 to 2019. The response rate was 44%. Radiographic linear wear rates were measured using the ROMAN software in patients who had completed questionnaires and had radiographs taken at least 10 years apart, leaving a final cohort of 249 patients (284 hips). Multivariate analyses were performed to determine the relationship between HXLPE wear rates and activity scores. Results: At the time of the survey, approximately 10% of the patients performed high-impact activities not-recommended by consensus guidelines. The HXLPE linear wear rate was 0.036 mm/year (SD: 0.026). Patients with higher activity levels, as measured on the continuous UCLA/HAAS activity scale, did not exhibit increased wear (β = -0.0009; p = 0.31). Stair climbing was correlated with increased wear rates (β = 0.0066; p = 0.004), whereas walking (β = 0.0005; p = 0.66) and running (β = 0.0017; p = 0.30) were not significantly correlated. Patients performing nonrecommended activities did not show increased wear rates compared with those performing recommended activities (β = 0.0063; p = 0.19). Conclusions: Linear wear rates of first-generation HXLPE were not related to functional activity or participation in high-impact activities. Future research should include longitudinal assessments of activity levels and data on other potential complications related to high-impact sports to provide robust evidence regarding recommended activity level postoperatively. Level of Evidence: Level III , Retrospective Comparative Study. See Instructions for Authors for a complete description of levels of evidence.

Background: Total joint arthroplasty (TJA) is increasingly being performed as an outpatient (i.e., same-day discharge) procedure. Postoperatively, orthostatic hypotension or pain-related tachycardia can lead to concerns regarding the hemoglobin (Hgb) level of the patient prior to discharge. The purpose of this study was to prospectively assess the reliability and accuracy of, and patient and nurse satisfaction with, postoperative noninvasive hemoglobin (nHgb) monitoring compared with an invasive serum hemoglobin (iHgb) laboratory draw in the outpatient TJA setting. Methods: We prospectively enrolled 200 patients undergoing outpatient unilateral TJA, of whom 157 were ultimately included in our analysis (94 hips, 63 knees). Postoperatively, both nHgb and iHgb values were obtained at a mean of 36 minutes apart. Surveys were completed by patients and nurses. The strength of the agreement between the 2 Hgb monitoring methods was evaluated with use of the Bland-Altman 95% limits of agreement, concordance correlation coefficient (CCC), and intraclass correlation coefficient (ICC). Receiver operating characteristic curve analyses were performed to investigate the ability of nHgb monitoring to predict an iHgb of <11.2 g/dL (the 5th-percentile iHgb value). Results: The mean preoperative iHgb was 14.2 ± 1.1 g/dL. The mean postoperative iHgb and nHgb values were 13.3 ± 1.5 and 13.3 ± 1.2 g/dL, respectively. The Bland-Altman 95% limits of agreement were −3.2 and +3.1 g/dL, indicating that 95% of patients’ iHgb values are expected to fall between these limits relative to the nHgb value of the patient. The CCC and ICC were both 0.33. An nHgb cutoff value of <12.7 g/dL had 100% sensitivity and 67% specificity for detecting an iHgb of <11.2 g/dL. Patients reported less pain with the nHgb test than with the iHgb test (mean pain score, 0.0 versus 1.8; p < 0.001), and 97% of patients preferred the nHgb test. Following the nHgb test, 73% of responding patients and 83% of responding nurses were “somewhat more reassured” to “significantly more reassured” about same-day discharge. Conclusions: Routine nHgb testing can rapidly screen patients undergoing outpatient TJA for acute anemia prior to discharge. With an nHgb of <12.7 g/dL, there was perfect sensitivity and 67% specificity for detecting an iHgb of <11.2 g/dL. Most patients and nurses felt more reassured about same-day discharge after nHgb monitoring. Level of Evidence: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Abstract The understanding and treatment of prearthritic hip disease has evolved remarkably over the past 20 years. The principal investigator and the multicenter Academic Network of Conservational Hip Outcomes Research (ANCHOR) group have had a key role in improving the quality of care for these patients suffering from the three most common prearthritic conditions: femoroacetabular impingement, developmental dysplasia of the hip, and residual Legg‐Calve‐Perthes Disease. We aim to demonstrate that based on the six quality of care dimensions as defined by Donabedian, our 20‐year academic journey has markedly improved the quality of care for young patients with prearthritic hip disease.

Case: A 20-year-old woman presented with a unipolar, 1.8 × 1.8-cm osteochondral defect of the left acetabulum. Osteochondral allograft transplantation was performed using a medial tibial plateau allograft resulting in excellent clinical outcomes across 4 different outcome scores and maintenance of the joint space at 4.3 years postoperatively. Conclusion: Although previous literature has demonstrated long-term clinical success of osteochondral allograft transplantation in knee, excellent clinical outcomes can also be obtained in the hip. Thus, osteochondral allograft transplantation may be a viable treatment option for adolescents and young adults with concomitant cartilage and subchondral bone hip defects.

Background: Metaphyseal cones with cemented stems can be successfully utilized in most revision total knee arthroplasties (TKAs). However, if the diaphysis has been previously violated, fixation of the cemented stem, which is important for cone ingrowth and construct survival, can be compromised. The initial results of our novel technique combining diaphyseal impaction bone-grafting with a metaphyseal cone were promising but required additional study. The purpose of the present study was to assess results of this technique in a larger cohort. Methods: A metaphyseal cone combined with diaphyseal impaction grafting and a cemented stem was utilized in 88 revision TKAs at our institution, including 35 from our prior study. The mean age at the time of revision was 67 years, and 67% of patients were male. Patients had had a mean of 4 prior knee arthroplasty procedures. The 2 most common reasons for revision were aseptic loosening (78%) and 2-stage reimplantation for periprosthetic joint infection (PJI) (19%). The mean follow-up was 4 years. Results: At the time of the latest follow-up, no cone-impaction grafting constructs required re-revision for aseptic loosening. Five-year survivorship free from any revision of the cone-impaction grafting construct and free from any reoperation was 95% and 65%, respectively. A total of 25 knees (28%) underwent reoperation, with the 2 most common indications being PJI and periprosthetic fracture. All cones were osseointegrated, and all bone graft appeared stable or incorporated. One patient had radiographic evidence of tibial component loosening despite a well-fixed cone; however, this patient was asymptomatic and had not undergone revision at 9 years. Conclusions: When presented with a sclerotic, polished diaphyseal canal with deficient cancellous bone and concomitant metaphyseal bone loss, our technique of combining diaphyseal impaction grafting with a metaphyseal cone proved extremely durable in this larger series of patients. No cone-impaction grafting constructs required re-revision for aseptic loosening. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.