Radiographically Apparent Acetabular Sourcil Landmarks Are Created by Comparable Regions of the Pelvis With Extraarticular Bone Variably Confounding Estimates of Joint Coverage.

BACKGROUND: The severity of hip dysplasia is characterized by radiographic measurements that require user definition of the acetabular sourcil edge, a bony landmark for which the corresponding three-dimensional (3D) anatomy is not well defined in any imaging plane. QUESTIONS/PURPOSES: To use digitally reconstructed radiographs to determine: (1) What 3D anatomy is contributing to the "acetabular sourcil" location used to make lateral center-edge angle (LCEA) and anterior center-edge angle (ACEA) measurements in standing AP and false-profile radiographic views, respectively? (2) How do intraobserver and interobserver agreement in LCEA and ACEA translate into agreement of the 3D anatomy being evaluated? (3) How distinct are regions around the acetabular rim circumference that are evaluated by LCEA and ACEA measurements on radiographs? METHODS: Between January 2018 and May 2019, 72 patients were indicated for periacetabular osteotomy to treat hip dysplasia or acetabular retroversion at our institution. From these patients, a series of 10 patients were identified of the first 12 patients in 2018 who were treated with periacetabular osteotomy, excluding two with missing or low-quality clinical imaging. A second series of 10 patients was identified of the first 11 patients in 2019 who were treated with periacetabular osteotomy and concurrent hip arthroscopy, excluding one who was missing clinical imaging. Pelvis and femoral bone surface models were generated from CT scans of these two series of 10 patients. There were 15 female and five male patients, with a median patient age of 18 years (IQR 17 to 23 years), a preoperative LCEA of 22° (IQR 18° to 24°), and a preoperative ACEA of 23° (IQR 18° to 27°). Exclusion criteria included missing preoperative CT or standard clinical radiographic imaging or severe joint incongruity. To address our first study question, digitally reconstructed radiographs matching each patient's standing AP and false-profile clinical radiographs were created from the segmented CT volumes. A board-certified orthopaedic surgeon and three trained researchers measured LCEA and ACEA on the digitally reconstructed radiographs, and the selected sourcil points were projected back into coordinates in the 3D anatomic space. To address our second study question, intraobserver and interobserver agreement in radiographic coverage angles were related to variations in 3D coordinates of the selected bony anatomy. Lastly, to address our third study question, 3D locations around the acetabular rim identified as contributing to the lateral and anterior sourcil points were summarized across patients in a clockface coordinate system, and statistical analysis of the "time" separating the 3D acetabular contributions of the sourcil edges was performed. RESULTS: The 3D anatomy contributing to the lateral sourcil was a variable length (27 mm [IQR 15 to 34 mm]) span of the laterosuperior acetabular edges, with contributions by the anterior inferior iliac spine in 35% (7 of 20) of hips. The anterior sourcil reflected a 28-mm (IQR 25 to 31 mm) span of bone from the medial ilium (posterior-medial to the anterior-inferior iliac spine and anterior-lateral to the arcuate line) to the anterior and lateral edges of the acetabulum. Interobserver variability was good for LCEA (intraclass correlation coefficient [ICC] 0.82 to 0.83) and moderate to good for ACEA (ICC 0.73 to 0.79), whereas the agreement in identified 3D sourcil locations varied widely (ICC 0.32 to 0.95). The acetabular edge of the 3D anatomy contributing to the anterior sourcil overlapped the circumferential range of the acetabular rim contributing to the lateral sourcil. CONCLUSION: Projection of two-dimensional radiographic landmarks contributing to the diagnosis of structural hip deformity into 3D allowed for the identification of the overlapping bony anatomy contributing to radiographically visible anterior and lateral sourcil edges. CLINICAL RELEVANCE: This work leveraging digitally reconstructed radiographs and 3D pelvis anatomy has found that bone outside the joint contributes to the radiographic appearance of the sourcil and may variably confound estimates of joint coverage. Furthermore, the substantial overlap between the acetabular bone contributing to measurement of the LCEA and ACEA would indicate that these angles measure similar acetabular deformity, and that additional measures are needed to assess anterior coverage independent of lateral coverage.

Loss of Muscle Mass and Strength After Hip Fracture: an Intervention Target for Nutrition Supplementation.

PURPOSEOF REVIEW: To summarize what is known about the deleterious effect of hip fracture on muscle mass and strength as well as the scientific evidence for post-surgical nutrition supplementation to maintain muscle and improve function. RECENT FINDINGS: This review provides a discussion of the relationship between muscle mass, strength, and physical function following hip fracture, briefly describes the approaches to measuring lean mass, discusses prevalence of sarcopenia and malnutrition among older men and women with hip fracture, and reviews the effects of essential amino acids on muscle. Loss of muscle mass and strength following hip fracture is substantial with consequences for recovery of functional independence. EAA-based nutrition supplementation, which directly effects muscle, has potential to improve outcomes.

Descriptive Epidemiology of Isolated Distal Radius Fractures in Children: Results From a Prospective Multicenter Registry.

INTRODUCTION: More than 1 in 4 pediatric fractures involves the distal radius. Most prior epidemiologic studies are limited to retrospective, single center investigations, and often include adults. This study aims to describe the contemporary epidemiology of pediatric distal radius fractures using prospectively collected data from a multicenter Pediatric Distal Radius Fracture Registry. METHODS: Patients aged 4 to 18 years diagnosed with a distal radius fracture from June 2018 through December 2019 at 4 tertiary care pediatric centers were screened and enrolled in this prospective longitudinal cohort study. Patients were excluded if they presented with bilateral distal radius fractures, polytrauma, or re-fracture. Demographic information, mechanism of injury, fracture characteristics, associated injuries, and procedural information were recorded. All radiographs were reviewed and measured. Descriptive statistics and bivariate analyses were performed. RESULTS: A total of 1951 patients were included. The mean age was 9.9±3.3 years, and 61.3% of patients were male ( P <0.001). Most injuries occurred during a high-energy fall (33.5%) or sports participation (28.4%). The greatest proportion of fractures occurred during the spring months (38.5%). Torus fractures (44.0%) were more common than bicortical (31.3%) or physeal (21.0%) fractures. Of the physeal fractures, 84.3% were Salter-Harris type II. Associated ulnar fractures were observed in 51.2% of patients. The mean age at injury was higher for patients with physeal fractures (11.6±2.9 y) than patients with torus or bicortical fractures (9.4±3.1 and 9.6±3.1 y, respectively; P <0.001). Thirty-six percent of distal radius fractures underwent closed reduction and 3.3% underwent surgical fixation. Patients treated with closed reduction were more likely to be male (68.7% vs. 57.2%; P <0.001), obese (25.3% vs. 17.2%; P <0.001), and have bicortical fractures (62.2% vs. 14.5%; P <0.001). CONCLUSIONS: Distal radius fractures in children have a male preponderance and are most likely to occur in the spring months and during high-energy falls and sports. Physeal fractures tend to occur in older children while torus and bicortical fractures tend to occur in younger children. LEVEL OF EVIDENCE: Level I-prognostic.

Cam Morphology Is Associated With Increased Femoral Version: Findings From a Collection of 1,321 Cadaveric Femurs.

BACKGROUND: To evaluate the relationship between femoral version (FV) and α angle (AA) in a large osteological collection of human femurs. METHODS: The University of Iowa-Stanford osteological collection was used to evaluate the research aims. To measure FV and AA, axial photographs of the proximal femurs were taken, referenced from the posterior condylar axis. FV and AA measurements were obtained using ImageJ software, and the relationship between FV and AA was assessed with repeated-measures analysis of variance and generalized linear models. A P value of <.05 was considered statistically significant. RESULTS: A total of 1321 cadaveric femurs (666 left and 655 right) in 721 cadavers were examined. The average AA for all femurs was 47.8° ± 10.9°, and the average FV for all femurs was 8.53° ± 8.09°. Overall, 191 femurs (14.5%) exhibited cam morphology (AA ≥ 60°). Of the 721 cadavers, 600 had both femurs available for side-to-side comparison. The average FV of femurs with cam morphology was significantly higher than that of femurs without cam morphology (11.70° ± 8.82° vs. 7.99° ± 8.82°, P < .001). Linear regression analysis demonstrated that increased AA was significantly correlated with increased FV (ß ± standard error of the mean = 0.21 ± 0.02, P < .0001). CONCLUSION: In a large osteological collection of human femurs, a significant positive relationship between AA and increasing FV was identified. CLINICAL RELEVANCE: FAI and hip impingement morphology are more complex than cam or pincer morphology. Cam morphology with high femoral anteversion may allow for normal or near-normal hip mechanics without impingement, and this may partially explain the high rates of asymptomatic cam-type femoroacetabular impingement (FAI) morphology in active and general populations. Given the multiple morphological factors implicated in the development of FAI syndrome, these findings warrant further investigation.

Hip Arthroscopy With and Without A Perineal Post: A Comparison of Early Postoperative Pain.

PURPOSE: To compare postoperative pain and early recovery after hip arthroscopy with and without a perineal post for joint distraction. METHODS: We retrospectively reviewed a consecutive series of patients who underwent hip arthroscopy before and after the adoption of a postless technique. Patients who underwent concurrent periacetabular or femoral osteotomy were excluded. Demographic information, procedure variables, and visual analog scale (VAS) pain scores were recorded. Analgesic medications given were converted to morphine milligram equivalents (MME) for comparison. Uni- and multivariate analyses were conducted to compare total MME, postoperative pain, and time to discharge between groups. RESULTS: One hundred patients were in each group. The overall age (mean ± standard deviation) was 26.5 ± 9.9 years (Post [P]: 57 females; No Post [NP]: 68 females). Total operative time (P 100.4 ± 17.9 minutes vs NP 89.1 ± 25.5 minutes, P = .0004), traction time (P 45.8 ± 10.3 minutes vs NP 40.9 ± 11.1 minutes, P = .0017), and operating room time (P 148.8 ± 19.3 minutes vs NP 137.3 ± 25.8 minutes, P = .0005) were found to be shorter in the NP group. Total MME, and final VAS pain scores in the PACU were similar between both groups (MME, P = .1620; VAS, P = .2139). Time to discharge was significantly shorter in the NP group (P 207.2 ± 58.8 vs NP 167.5 ± 47.9, P < .0001). Patient age (≥25 years) (65.2 ± 18.1 vs 59.8 ± 15.7 [MME], P = .0269) and elevated body mass index (≥25) (65.1 ± 17.1 vs 59.3 ± 16.4 [MME], P = .0164) were factors associated with greater total MME consumption. Female sex was associated with higher postoperative VAS pain scores (FM 4.1 ± 1.6 vs M 3.4 ± 1.8 P = .0027). CONCLUSIONS: Adoption of the postless technique did not result in prolonged operating room or operative time. Overall, both groups had similar postoperative pain, however, the time from surgery to hospital discharge was shorter in the postless group. LEVEL OF EVIDENCE: III, retrospective comparison study.

Acceptance and Commitment Therapy Delivered via a Mobile Phone Messaging Robot to Decrease Postoperative Opioid Use in Patients With Orthopedic Trauma: Randomized Controlled Trial.

BACKGROUND: Acceptance and commitment therapy (ACT) is a pragmatic approach to help individuals decrease avoidable pain. OBJECTIVE: This study aims to evaluate the effects of ACT delivered via an automated mobile messaging robot on postoperative opioid use and patient-reported outcomes (PROs) in patients with orthopedic trauma who underwent operative intervention for their injuries. METHODS: Adult patients presenting to a level 1 trauma center who underwent operative fixation of a traumatic upper or lower extremity fracture and who used mobile phone text messaging were eligible for the study. Patients were randomized in a 1:1 ratio to either the intervention group, who received twice-daily mobile phone messages communicating an ACT-based intervention for the first 2 weeks after surgery, or the control group, who received no messages. Baseline PROs were completed. Two weeks after the operative intervention, follow-up was performed in the form of an opioid medication pill count and postoperative administration of PROs. The mean number of opioid tablets used by patients was calculated and compared between groups. The mean PRO scores were also compared between the groups. RESULTS: A total of 82 subjects were enrolled in the study. Of the 82 participants, 76 (38 ACT and 38 controls) completed the study. No differences between groups in demographic factors were identified. The intervention group used an average of 26.1 (SD 21.4) opioid tablets, whereas the control group used 41.1 (SD 22.0) tablets, resulting in 36.5% ([41.1-26.1]/41.1) less tablets used by subjects receiving the mobile phone-based ACT intervention (P=.004). The intervention group subjects reported a lower postoperative Patient-Reported Outcome Measure Information System Pain Intensity score (mean 45.9, SD 7.2) than control group subjects (mean 49.7, SD 8.8; P=.04). CONCLUSIONS: In this study, the delivery of an ACT-based intervention via an automated mobile messaging robot in the acute postoperative period decreased opioid use in selected patients with orthopedic trauma. Participants receiving the ACT-based intervention also reported lower pain intensity after 2 weeks, although this may not represent a clinically important difference. TRIAL REGISTRATION: ClinicalTrials.gov NCT03991546; https://clinicaltrials.gov/ct2/show/NCT03991546.

Patient Age and Hip Morphology Alter Joint Mechanics in Computational Models of Patients With Hip Dysplasia.

BACKGROUND: Older patients (> 30 years) undergoing periacetabular osteotomy (PAO) to delay THA often have inferior patient-reported outcomes than younger adult patients (< 30 years). It is unclear how patient age affects hip morphology, mechanics, or patient-reported outcome scores. QUESTIONS/PURPOSES: (1) Is increased patient age associated with computationally derived elevations in joint contact stresses? (2) Does hip shape affect computationally derived joint contact stresses? (3) Do computationally derived joint contact stresses correlate with visual analog scale (VAS) pain scores evaluated at rest in the clinic at a minimum of 1 year after surgery? METHODS: A minimum of 1 year of clinical followup was required for inclusion. The first 15 patients younger than 30 years of age, and the first 15 patients older than 30 years of age, who underwent PAO for treatment of classic dysplasia (lateral center-edge angle < 25°) who met the minimum followup were selected from a historical database of patients treated by a single surgeon between April 2003 and April 2010. The older cohort consisted of 14 females and one male with a median age of 41 years (range, 31-54 years). The younger cohort consisted of 10 females and five males with a median age of 19 years (range, 12-29 years). Median followup for the older than 30 years versus younger than 30 years cohort was 19 months (range, 12-37 months) versus 24 months (range, 13-38 months). Pre- and postoperative hip models were created from CT scans for discrete element analysis (DEA) contact stress computations. DEA treats contacting articular surfaces as rigid bodies (bones) separated by a bed of compressive springs (cartilage), the deformation of which governs computation of joint contact stresses. This technique greatly simplifies computational complexity compared with other modeling techniques, which permits patient-specific modeling of larger cohorts. Articular surface shape was assessed by total root mean square deviation of each patient's acetabular and femoral cartilage geometry from sphericity. Preoperative and postoperative VAS pain scores evaluated at rest in the clinic were correlated with computed contact stresses. RESULTS: Patients older than 30 years had higher predicted median peak contact stress preoperatively (13 MPa [range, 9-23 MPa; 95% confidence interval {CI}, 11-15 MPa] versus 7 MPa [range, 6-14 MPa; 95% CI, 6-8 MPa], p < 0.001) but not postoperatively (10 MPa [range, 6-18 MPa; 95% CI, 8-12 MPa] versus 8 MPa [range, 6-13 MPa; 95% CI, 7-9 MPa], p = 0.137). Deviation from acetabular sphericity positively correlated with preoperative peak contact stress (R = 0.326, p = 0.002) and was greater in the older cohort (0.9 mm [range, 0.8-1.5 mm; 95% CI, 0.8-1.0 mm] versus 0.8 mm [range, 0.6-0.9 mm; 95% CI, 0.7-0.9 mm], p = 0.014). Peak preoperative contact stress did not correlate with preoperative VAS pain score (R = 0.072, p = 0.229), and no correlation was found between change in peak contact stress and change in VAS score (R = 0.019, p = 0.280). CONCLUSIONS: Patients over the age of 30 years with dysplasia had less spherical acetabula and higher predicted preoperative contact stress than those younger than 30 years of age. Future studies with larger numbers of patients and longer term functional outcomes will be needed to determine the role of altered mechanics in the long-term success of PAO varying with patient age. CLINICAL RELEVANCE: These findings suggest that long-term exposure to abnormal joint loading may have deleterious effects on the hip geometry and may render the joint less amenable to joint preservation procedures. Given the lack of a direct relationship between mechanics and pain, orthopaedic surgeons should be particularly critical when evaluating three-dimensional dysplastic hip morphology in patients older than 30 years of age to ensure beneficial joint reorientation.

Pain Management for Periacetabular Osteotomy: A Systematic Review.

Background: Early post-operative pain control is essential to facilitate rapid recovery after orthopaedic surgery. Despite periacetabular osteotomy (PAO) being the gold standard treatment of prearthritic hip dysplasia, there is limited evidence assessing efficacy of early post-operative pain management strategies. Recent literature has focused on non-opioid supplemental treatments such as nerve blocks or local wound infiltration. The purpose of this systematic review was to assess efficacy of these interventions to reduce pain, facilitate mobilization, reduce length of stay after PAO surgery. Methods: A systematic review was created under the guidance of PRISMA from databases that included PubMed, OVID Medline, Embase, SCOPUS, Cochrane Central Register of Clinical Trials, and clinicaltrials.gov from their creation dates to 12/21/23. These studies were screen based on predetermined inclusion and exclusion criteria. Results: A total of six studies were included in this analysis from independent institutions. Three investigated nerve blocks (fascia iliaca, pericapsular, transversus abdominis), one investigated local wound infiltration with ropivacaine, one investigated high-dose dexamethasone, and the last investigated removal of the epidural catheter on postoperative (POD) 1 compared to POD 2. There were heterogeneous outcomes that were measured from these studies. In general, nerve blocks decreased opioid use, pain, and length of hospital stay. The local wound infiltration decreased pain on POD 3 and 4. Removing the epidural catheter on POD1 compared to POD 2 decreased pain and length of stay. High-dose dexamethasone use decreased opioid use on POD 1, otherwise, there was no difference in pain. Conclusion: In summary, supplemental pain management strategies peri-operatively for PAO surgery can decrease pain, opioid use, and length of hospital stay, though there are few studies assessing these interventions. Limiting opioid use after surgery reduces known negative consequences of the medication and facilitates rapid recovery. Clinical trials are needed that assess efficacy of supplemental pain management strategies after PAO surgery. Level of Evidence: II.

Hip Dysplasia Treated With Periacetabular Osteotomy in Patients Over 40 Years Old: A Systematic Review.

Background: Hip dysplasia is a leading cause of hip osteoarthritis. While periacetabular osteotomy (PAO) is effective for relieving pain and dysfunction caused by hip dysplasia in adolescents and young adults, there is concern that patients over 40 years of age will have an increased risk of persistent dysfunction and need for total hip arthroplasty. Current available evidence for PAO in older adults is limited and there is no systematic review in the literature focusing on this topic. The current systematic review offers insight into the demographics, patient-reported outcome measure (PROM) scores, and hip survivorship from total hip arthroplasty in patients over 40 years older treated for hip dysplasia with PAO. Methods: The review was conducted under the guidelines for the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). Databases that were searched included PubMed, OVID Medline, SCOPUS, Embase, Cochrane Library, and clinicaltrials.gov. Studies were screened based on predetermined inclusion and exclusion criteria. Results: Five studies were included in this systematic review. Enrollment years were 1990-2013. In total, there were 335 hips with mean ages between 43.5-47.2 years. Mean follow up was 4-10.8 years. Most patients that underwent hip preservation had Tonnis osteoarthritis grade 0-1. There was contradicting evidence whether patients >40 years did better or worse compared to <40 years; although, most patients in the >40 years group had good outcomes after PAO. PAO survivorship ranged from 67-100% depending on the study. Complications ranged from 2-36% of cases depending on the study; although, none of these complications had lasting effects. Conclusion: Patients over 40 years old appear to have positive outcomes when treated for hip dysplasia with PAO, though these patients were likely selected for no to minimal osteoarthritis, high functional status, and good health. PAO should be considered for patients with hip dysplasia over 40 years old without hip arthritis, though we recommend very selective indications. Level of Evidence: II.

Prevalence of Radiographic Hip Dysplasia in the General Adult Population: A Systematic Review.

Background: Acetabular dysplasia has a wide range of prevalence reported in the literature. This variation is likely due to differences in the population under investigation and studies focusing on cohorts with hip pain and osteoarthritis. There are reports of radiographic hip dysplasia prevalence for adults without hip pain but there is no systematic review of these studies to document the incidence in the general population. The purpose of this systematic review was to provide a full summary of all studies that report prevalence of hip dysplasia in adults without hip pain. Methods: PRISMA guidelines were utilized as an outline for this systematic review. Articles were pulled from PubMed, OVID Medline, Embase, SCOPUS, Cochrane Central Register of Clinical Trials, and clinicaltrials.gov from their inception dates to 1/7/24. Studies were included if participants were asymptomatic and reported rates of prevalence. Results: Fourteen studies were included in this systematic review. There were 10,998 hips from 5,506 participants included in this analysis. The overall prevalence of radiographic hip dysplasia was 2.3%. Eight studies of 5,930 hips reported the prevalence of hip dysplasia by sex. The prevalence rate in these studies was 3.8% in females and 2.7% in males. Conclusion: Acetabular dysplasia based on radiographic measurements is relatively common in the general adult population. Furthermore, females have a higher prevalence rate when compared to males. It is important to recognize the incidence of hip dysplasia in the asymptomatic adult population as we recommend surgical treatment for patients who present with hip pain and dysplasia. Further studies should investigate the natural history of untreated and treated hip dysplasia. Level of Evidence: III.

Incorporating patient-specific hip orientation from weightbearing computed tomography affects discrete element analysis-computed regional joint contact mechanics in individuals treated with periacetabular osteotomy for hip dysplasia.

Computational models of the hip often omit patient-specific functional orientation when placing imaging-derived bony geometry into anatomic landmark-based coordinate systems for application of joint loading schemes. The purpose of this study was to determine if this omission meaningfully alters computed contact mechanics. Discrete element analysis models were created from non-weightbearing (NWB) clinical CT scans of 10 hip dysplasia patients (11 hips) and oriented in the International Society of Biomechanics (ISB) coordinate system (NWB-ISB). Three additional models were generated for each hip by adding patient-specific stance information obtained via weightbearing CT (WBCT) to each ISB-oriented model: (1) patient-specific sagittal tilt added (WBCT-sagittal), (2) coronal and axial rotation from optical motion capture added to (1; WBCT-combo), and (3) WBCT-derived axial, sagittal, and coronal rotation added to (1; WBCT-original). Identical gait cycle loading was applied to all models for a given hip, and computed contact stress and contact area were compared between model initialization techniques. Addition of sagittal tilt did not significantly change whole-joint peak (p = 0.922) or mean (p = 0.871) contact stress or contact area (p = 0.638). Inclusion of motion-captured coronal and axial rotation (WBCT-combo) decreased peak contact stress (p = 0.014) and slightly increased average contact area (p = 0.071) from WBCT-sagittal models. Including all WBCT-derived rotations (WBCT-original) further reduced computed peak contact stress (p = 0.001) and significantly increased contact area (p = 0.001). Variably significant differences (p = 0.001-1.0) in patient-specific acetabular subregion mechanics indicate the importance of functional orientation incorporation for modeling applications in which local contact mechanics are of interest.

Persistently elevated joint contact stress after periacetabular osteotomy is associated with joint failure at minimum 10-year follow-up.

Periacetabular osteotomy (PAO) is a common treatment for prearthritic hip dysplasia. The goal of this investigation was to determine if computationally assessed hip contact mechanics are associated with joint failure at minimum 10-year follow-up. One hundred patients with hip dysplasia (125 hips) completed patient-reported outcomes an average of 13.8 years (range 10.0-18.0 years) after PAO. 63/125 hips were classified as having failed: 26 converted to total hip arthroplasty (THA) and 37 with significant disability indicated by modified Harris Hip Score (mHHS) ≤ 70. Differences in discrete element analysis-computed contact mechanics were compared between (1) preserved and failed hips, (2) preserved hips and hips that failed by THA, and (3) preserved hips and hips that failed by mHHS ≤ 70. Failed hips had significantly higher preoperative contact stress and exposure metrics (p < 0.001-0.009) than preserved hips. Failed hips also had significantly higher postoperative peak contact stress (p = 0.018), higher mean contact stress (p < 0.001), and smaller contact area (p = 0.044). When assessed based on type of failure, hips that failed by THA had significantly higher postoperative contact stress and exposure metrics than preserved hips (p < 0.001-0.020). In hips that failed by mHHS ≤ 70, mean postoperative contact stress exposure was significantly higher compared to preserved hips (p = 0.043). Despite improved radiographic measures of dysplasia after PAO, pathologic joint contact mechanics can persist and predict treatment failure at minimum 10 years after surgery. Operative and nonoperative techniques specifically intended to reduce harmful contact mechanics in dysplastic hips may have the potential to further improve clinical outcomes after PAO.

Resident Synovial Macrophages in Synovial Fluid: Implications for Immunoregulation in Infectious and Inflammatory Arthritis.

Objectives: Resident synovial macrophages (RSM) provide immune sequestration of the joint space and are likely involved in initiation and perpetuation of the joint-specific immune response. We sought to identify RSM in synovial fluid (SF) and demonstrate migratory ability, in additional to functional changes that may perpetuate a chronic inflammatory response within joint spaces. Methods: We recruited human patients presenting with undifferentiated arthritis in multiple clinical settings. We used flow cytometry to identify mononuclear cells in peripheral blood and SF. We used a novel transwell migration assay with human ex-vivo synovium obtained intra-operatively to validate flow cytometry findings. We used single cell RNA-sequencing (scRNA-seq) to further identify macrophage/monocyte subsets. ELISA was used to evaluate the bone-resorption potential of SF. Results: We were able to identify a rare population of CD14dim, OPG+, ZO-1+ cells consistent with RSM in SF via flow cytometry. These cells were relatively enriched in the SF during infectious processes, but absolutely decreased compared to healthy controls. Similar putative RSM were identified using ex vivo migration assays when MCP-1 and LPS were used as migratory stimulus. scRNA-seq revealed a population consistent with RSM transcriptionally related to CD56+ cytotoxic dendritic cells and IDO+ M2 macrophages. Conclusion: We identified a rare cell population consistent with RSM, indicating these cells are likely migratory and able to initiate or coordinate both acute (septic) or chronic (autoimmune or inflammatory) arthritis. RSM analysis via scRNA-seq indicated these cells are M2 skewed, capable of antigen presentation, and have consistent functions in both septic and inflammatory arthritis.

Sex Differences in Patient-Reported Outcomes Following Surgical Hip Preservation Interventions: A Systematic Review and Meta-Analysis.

Background: Female patients undergoing hip preservation surgery often have inferior patient-reported outcome scores (PROs), raising concerns about the clinical benefit of hip preservation surgery in women. Comparison of preoperative and postoperative PROs, and change in PROs, for female versus (vs.) male hip preservation patients was completed via systematic review. Methods: In accordance with PRISMA guidelines, the MEDLINE, Cochrane Central, and Em-base databases were searched. Level I-IV studies of patients undergoing surgical intervention for femoroacetabular impingement (FAI) and/or developmental dysplasia of the hip (DDH) with at least two years of postoperative follow-up were included. Sex-stratified PRO scores or outcome information had to be included. Results: We identified 32 hip preservation studies evaluating sex-related PRO differences, and/or providing sex-specific PRO data. The quantitative analysis of 24 studies (1843 patients) was stratified by DDH status. The modified Harris Hip Score (mHHS), Hip Outcome Score-Activities of Daily Living subscale (HOS-ADL), and Hip Outcome Score-Sport-Specific subscale (HOS-SSS) were assessed. Patients undergoing surgery for FAI only were 52.1% female (n= 806/1546). As predicted, women had lower preoperative PRO scores, however, they had significantly greater improvements in HOS-ADL (20.14±4.41 vs. 26.00±0.35, p<0.05) and HOS-SSS (33.21± 0.71 vs. 38.33± 0.46, p<0.05) compared to males. Similar results were found in the DDH cohort of 330 patients (72.1% female): females had lower preoperative PRO scores, but significantly greater improvement of mHHS (22.68±0.45 vs. 10.60±1.46, p<0.01). Conclusion: The present review suggests that men undergoing surgery for FAI and/or DDH tend to have higher preoperative and postoperative PRO scores. However, it appears that women often have greater preoperative to postoperative improvement in PRO scores. This finding is strongest in surgical treatment of DDH. Level of Evidence: III.

Use of Conditionally Essential Amino Acids and the Economic Burden of Postoperative Complications After Fracture Fixation: Results from a Cost Utility Analysis.

Objective: To measure the economic impact of conditionally essential amino acids (CEAA) among patients with operative treatment for fractures. Methods: A decision tree model was created to estimate changes in annual health care costs and quality of life impact due to complications after patients underwent operative treatment to address a traumatic fracture. The intervention of interest was the use of CEAA alongside standard of care as compared to standard of care alone. Patients were required to be aged ≥18 and receive the surgery in a US Level 1 trauma center. The primary outcomes were rates of post-surgical complications, changes in patient quality adjusted life years (QALYs), and changes in cost. Cost savings were modeled as the incremental costs (in 2022 USD) of treating complications due to changes in complication rates. Results: The per-patient cost of complications under CEAA use was $12,215 compared to $17,118 under standard of care without CEAA. The net incremental cost savings per patient with CEAA use was $4902, accounting for a two-week supply cost of CEAA. The differences in quality-adjusted life years (QALYs) under CEAA use and no CEAA use was 0.013 per person (0.739 vs 0.726). Modeled to the US population of patients requiring fracture fixations in trauma centers, the total value of CEAA use compared to no CEAA use was $316 million with an increase of 813 QALYs per year. With a gain of 0.013 QALYs per person, valued at $150,000, and the incremental cost savings of $4902 resulted in net monetary benefit of $6852 per patient. The incremental cost-effectiveness ratio showed that the use of CEAA dominated standard of care. Conclusion: CEAA use after fracture fixation surgery is cost saving. Level of Evidence: Level 1 Economic Study.

Joint contact stress improves in dysplastic hips after periacetabular osteotomy but remains higher than in normal hips.

AIM: The purpose of this study was to use computational modeling to determine if surgical correction of hip dysplasia restores hip contact mechanics to those of asymptomatic, radiographically normal hips. METHODS: Discrete element analysis (DEA) was used to compute joint contact stresses during the stance phase of normal walking gait for 10 individuals with radiographically normal, asymptomatic hips and 10 age- and weight-matched patients with acetabular dysplasia who underwent periacetabular osteotomy (PAO). RESULTS: Mean and peak contact stresses were higher (p < 0.001 and p = 0.036, respectively) in the dysplastic hips than in the matched normal hips. PAO normalised standard radiographic measurements and medialised the location of computed contact stress within the joint. Mean contact stress computed in dysplastic hips throughout the stance phase of gait (median 5.5 MPa, [IQR 3.9-6.1 MPa]) did not significantly decrease after PAO (3.7 MPa, [IQR 3.2-4.8]; p = 0.109) and remained significantly (p < 0.001) elevated compared to radiographically normal hips (2.4 MPa, [IQR 2.2-2.8 MPa]). Peak contact stress demonstrated a similar trend. Joint contact area during the stance phase of gait in the dysplastic hips increased significantly (p = 0.036) after PAO from 395 mm2 (IQR 378-496 mm2) to 595 mm2 (IQR 474-660 mm2), but remained significantly smaller (p = 0.001) than that for radiographically normal hips (median 1120 mm2, IQR 853-1444 mm2). CONCLUSIONS: While contact mechanics in dysplastic hips more closely resembled those of normal hips after PAO, the elevated contact stresses and smaller contact areas remaining after PAO indicate ongoing mechanical abnormalities should be expected even after radiographically successful surgical correction.

Biomechanical guidance can improve accuracy of reduction for intra-articular tibia plafond fractures and reduce joint contact stress.

Articular fracture malreduction increases posttraumatic osteoarthritis (PTOA) risk by elevating joint contact stress. A new biomechanical guidance system (BGS) that provides intraoperative assessment of articular fracture reduction and joint contact stress based solely on a preoperative computed tomography (CT) and intraoperative fluoroscopy may facilitate better fracture reduction. The objective of this proof-of-concept cadaveric study was to test this premise while characterizing BGS performance. Articular tibia plafond fractures were created in five cadaveric ankles. CT scans were obtained to provide digital models. Indirect reduction was performed in a simulated operating room once with and once without BGS guidance. CT scans after fixation provided models of the reduced ankles for assessing reduction accuracy, joint contact stresses, and BGS accuracy. BGS was utilized 4.8 ± 1.3 (mean ± SD) times per procedure, increasing operative time by 10 min (39%), and the number of fluoroscopy images by 31 (17%). Errors in BGS reduction assessment compared to CT-derived models were 0.45 ± 0.57 mm in translation and 2.0 ± 2.5° in rotation. For the four ankles that were successfully reduced and fixed, associated absolute errors in computed mean and maximum contact stress were 0.40 ± 0.40 and 0.96 ± 1.12 MPa, respectively. BGS reduced mean and maximum contact stress by 1.1 and 2.6 MPa, respectively. BGS thus improved the accuracy of articular fracture reduction and significantly reduced contact stress. Statement of Clinical Significance: Malreduction of articular fractures is known to lead to PTOA. The BGS described in this work has potential to improve quality of articular fracture reduction and clinical outcomes for patients with a tibia plafond fracture.

What Are the Barriers to Incorporating Nutrition Interventions Into Care of Older Adults With Femoral Fragility Fractures?

Femoral fragility fractures cause substantial morbidity and mortality in older adults. Mortality has generally been approximated between 10-20% in the first year after fracture and among those who do survive, another 20-60% require assistance with basic activities within 1-2 years following fracture.1 Malnutrition is common and perpetuates these poor outcomes. Nutrition supplementation has potential to prevent post-injury malnutrition, preserve functional muscle mass, and improve outcomes in older adults with femoral fragility fractures, however high-quality evidence is lacking, thus limiting translation of interventions into clinical practice. This review article is designed to highlight gaps in the evidence investigating nutrition interventions in this population and identify barriers for translation to clinical practice. Our goal is to guide future nutrition intervention research in older adults with femoral fragility fractures. Level of Evidence: V.

Substantial Loss of Skeletal Muscle Mass Occurs After Femoral Fragility Fracture.

BACKGROUND: Femoral fragility fractures in older adults can result in devastating loss of physical function and independence. Skeletal muscle atrophy likely contributes to disability. The purpose of this study was to characterize the change in skeletal muscle mass, investigate the relationship with malnutrition and physical function, and identify risk factors for skeletal muscle loss. METHODS: Adults ≥65 years of age who were treated with operative fixation of an isolated femoral fragility fracture were enrolled in this multicenter, prospective observational study. Skeletal muscle mass was assessed within 72 hours of admission using multifrequency bioelectrical impedance analysis, which was repeated at 6 weeks, 3 months, and 6 months. Sarcopenia was defined by sex-specific cutoffs for the appendicular skeletal muscle mass index. The Mini Nutritional Assessment was used to measure nutritional status at the time of injury. Physical function was measured using the Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function domain. Linear mixed models were used to evaluate changes in skeletal muscle mass and PROMIS Physical Function scores over time and to evaluate factors associated with skeletal muscle mass changes. RESULTS: Ninety participants (74% female) with a mean age of 77.6 ± 9.0 years were enrolled. At the time of injury, 30 (33%) were sarcopenic and 44 (49%) were at risk for malnutrition or had malnutrition. Older age was associated with lower skeletal muscle mass (age of ≥75 versus <75 years: least squares mean [and standard error], -3.3 ± 1.6 kg; p = 0.042). From the time of injury to 6 weeks, participants lost an average of 2.4 kg (9%) of skeletal muscle mass (95% confidence interval [CI] = ‒3.0 to ‒1.8 kg; p < 0.001). This early loss did not recover by 6 months (1.8 kg persistent loss compared with baseline [95% CI = ‒2.5 to ‒1.1 kg]; p < 0.001). Participants with normal nutritional status lost more skeletal muscle mass from baseline to 6 weeks after injury compared with those with malnutrition (1.3 kg more loss [standard error, 0.6 kg]; p = 0.036). A 1-kg decrease in skeletal muscle mass was associated with an 8-point decrease in the PROMIS Physical Function (model parameter estimate, 0.12 [standard error, 0.04]; p = 0.002). CONCLUSIONS: We found that older adults with femoral fragility fractures lost substantial skeletal muscle mass and physical function. Participants with adequate baseline nutrition actually lost more muscle mass than those who were malnourished, indicating that future investigations of interventions to prevent muscle loss should focus on older adults regardless of nutritional status. LEVEL OF EVIDENCE: Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Providing a computationally derived, mechanically optimised target correction during preoperative planning can improve joint contact mechanics of hip dysplasia treated with periacetabular osteotomy.

AIM: Preoperative identification of acetabular corrections that optimally improve joint stability and reduce elevated contact stresses could further reduce osteoarthritis progression in patients with hip dysplasia who are treated with periacetabular osteotomy (PAO). The purpose of this study was to investigate how providing patient-specific, mechanically optimal acetabular reorientations to the surgeon during preoperative planning affected the surgically achieved correction. METHODS: Preoperative CT scans were used to create patient-specific hip models for 6 patients scheduled for PAO. A simulated acetabular fragment was extracted from the preoperative pelvis model and computationally rotated to simulate candidate acetabular reorientations. For each candidate, discrete element analysis was used to compute contact stresses during walking, which were summed over the gait cycle and scaled by patient age to obtain chronic contact stress-time exposure. The ideal patient-specific reorientation was identified using a cost function that balances minimising chronic stress exposures and achieving surgically acceptable acetabular coverage angles. The optimal reorientation angles and associated contact mechanics were provided to the surgeon preoperatively. After PAO was performed, a model of the surgically achieved correction was created from a postoperative CT scan. Radiographic coverage and contact mechanics were compared between preoperative, optimal, and surgically achieved orientations. RESULTS: While surgically achieved reorientations were not significantly different from optimal reorientations in radiographically measured lateral (p = 0.094) or anterior (p = 0.063) coverage, surgically achieved reorientations had significantly (p = 0.031) reduced total contact area compared to optimal reorientations. The difference in lateral coverage and peak chronic exposure between surgically achieved and optimal reorientations decreased with increasing surgeon experience using the models (R² = 0.758, R2 = 0.630, respectively). CONCLUSIONS: Providing hip surgeons with a patient-specific, computationally optimal reorientation during preoperative planning may improve contact mechanics after PAO, which may help reduce osteoarthritis progression in patients with hip dysplasia.