Exploring the overlap between alopecia areata and major depressive disorder: Epidemiological and genetic perspectives.

BACKGROUND: Research suggests that Alopecia areata (AA) and Major Depressive Disorder (MDD) show substantial comorbidity. To date, no study has investigated the hypothesis that this is attributable to shared genetic aetiology. OBJECTIVES: To investigate AA-MDD comorbidity on the epidemiological and molecular genetic levels. METHODS: First, epidemiological analyses were performed using data from a cohort of adult German health insurance beneficiaries (n = 1.855 million) to determine the population-based prevalence of AA-MDD comorbidity. Second, analyses were performed to determine the prevalence of MDD in a clinical AA case-control sample with data on psychiatric phenotypes, stratifying for demographic factors to identify possible contributing factors to AA-MDD comorbidity. Third, the genetic overlap between AA and MDD was investigated using a polygenic risk score (PRS) approach and linkage disequilibrium score (LDSC) regression. For PRS, summary statistics from a large MDD GWAS meta-analysis (PGC-MD2) were used as the training sample, while a Central European AA cohort, including the above-mentioned AA patients, and an independent replication US-AA cohort were used as target samples. LDSC was performed using summary statistics of PGC-MD2 and the largest AA meta-analysis to date. RESULTS: High levels of AA-MDD comorbidity were reported in the population-based (MDD in 24% of AA patients), and clinical samples (MDD in 44% of AA patients). MDD-PRS explained a modest proportion of variance in AA case-control status (R2  = 1%). This signal was limited to the major histocompatibility complex (MHC) region on chromosome 6. LDSC regression (excluding MHC) revealed no significant genetic correlation between AA and MDD. CONCLUSIONS: As in previous research, AA patients showed an increased prevalence of MDD. The present analyses suggest that genetic overlap may be confined to the MHC region, which is implicated in immune function. More detailed investigation is required to refine understanding of how the MHC is involved in the development of AA and MDD comorbidity.

Genomic profiling of late-onset basal cell carcinomas from two brothers with nevoid basal cell carcinoma syndrome.

BACKGROUND: Nevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant genetic disorder. It is commonly caused by mutations in PTCH1 and chiefly characterized by multiple basal cell carcinomas (BCCs) developing prior to the age of 30 years. In rare cases, NBCCS presents with a late onset of BCC development. OBJECTIVE: To investigate BCC tumorigenesis in two brothers, who showed characteristic features of NBCCS but developed their first BCCs only after the age of 40 years. Two other siblings did not show signs of NBCCS. RESULTS: We obtained blood samples from four siblings and nine BCCs from the two brothers with NBCCS. Whole exome sequencing and RNA sequencing revealed loss of heterozygosity (LOH) of PTCH1 in eight out of nine tumours that consistently involved the same haplotype on chromosome 9. This haplotype contained a germinal splice site mutation in PTCH1 (NM_001083605:exon9:c.763-6C>A). Analysis of germline DNA confirmed segregation of this mutation with the disease. All BCCs harboured additional somatic loss-of-function (LoF) mutations in the remaining PTCH1 allele which are not typically seen in other cases of NBCCS. This suggests a hypomorphic nature of the germinal PTCH1 mutation in this family. Furthermore, all BCCs had a similar tumour mutational burden compared to BCCs of unrelated NBCCS patients while harbouring a higher number of damaging PTCH1 mutations. CONCLUSIONS: Our data suggest that a sequence of three genetic hits leads to the late development of BCCs in two brothers with NBCCS: a hypomorphic germline mutation, followed by somatic LOH and additional mutations that complete PTCH1 inactivation. These genetic events are in line with the late occurrence of the first BCC and with the higher number of damaging PTCH1 mutations compared to usual cases of NBCCS.

Thermogenic and psychogenic sweating in humans: Identifying eccrine glandular recruitment patterns from glabrous and non-glabrous skin surfaces.

In this experiment, psychogenic (mental arithmetic), thermogenic (mean body temperature elevation of 0.6 °C) and combined thermo-psychogenic treatments were used to explore eccrine sweat-gland recruitment from glabrous (volar hand and forehead) and non-glabrous skin surfaces (chest). It was hypothesised that each treatment would activate the same glands, and that glandular activity would be intermittent. Nine individuals participated in a single trial with normothermic and mildly hyperthermic phases. When normothermic, a 10-min arithmetical challenge was administered, during which sudomotor activity was recorded. Following passive heating and thermal clamping, sweating responses were again evaluated (10 min). A second arithmetical challenge (10 min) was administered during clamped hyperthermia, with its sudorific impact recorded. The activity of individual sweat glands was recorded at 60-s intervals, using precisely positioned, and uniformly applied, starch-iodide papers. Those imprints were digitised and analysed. Peak activity typically occurred during the thermo-psychogenic treatment, revealing physiologically active densities of 128 (volar hand), 165 (forehead) and 77 glands.cm-2 (chest). Except for the hand (46%), glands uniquely activated by one treatment were consistently <10% of the total glands identified. Glandular activations were most commonly of an intermittent nature, particularly during the thermogenic treatment. Accordingly, we accepted the hypothesis that psychogenic, thermogenic and thermo-psychogenic stimuli activate the same sweat glands in both the glabrous and non-glabrous regions. In addition, this investigation has provided detailed descriptions of the intermittent nature of sweat-gland activity, revealing that a consistent proportion of the physiologically active glands are recruited during these thermal and non-thermal stimuli.

Positive FABER distance test is associated with higher alpha angle in symptomatic patients.

PURPOSE: The purpose of this study was to determine the diagnostic value of the flexion abduction external rotation (FABER) distance test (FDT) for the diagnosis of cam-type femoroacetabular impingement (FAI) as defined by alpha angle. METHODS: For this study, 603 patients with symptomatic, unilateral femoroacetabular impingement were included. Patients with symptoms of hip instability, bilateral symptoms, bilateral surgery, or bilateral alpha angles over 55 were excluded from the analysis. A positive FDT was defined as a difference of 4 cm or more between hips. A pathological cam was defined as an alpha angle of 78° or greater. RESULTS: The average age was 36.4 ± 12 years, with 344 males and 259 females. Faber distance of the injured hip was correlated with age at surgery (rho = 0.148; p < 0.001). Alpha angle on the injured hip was positively correlated with injured hip FABER distance (rho = 0.276; p < 0.001). The average alpha angle in patients with a positive FABER distance test was 74° (SD = 11°) compared to 68° (SD = 8°) in patients with a negative distance test (p = 0.001). The sensitivity of the FDT to diagnose pathological cam was 0.848 (0.79-0.89) with a negative predictive value of 86% (81-90%). CONCLUSION: This study demonstrated that the FABER distance test is correlated with the alpha angle and is a good diagnostic exam for pathological cam-type FAI as defined by and alpha angle equal to or greater than 78°. CLINICAL RELEVANCE: FABER distance test is a simple test that can be used as a screening test to decide if FAI should be suspected and further testing is needed. LEVEL OF EVIDENCE: III.

An Open-Label Pilot Study to Evaluate the Efficacy of Tofacitinib in Moderate to Severe Patch-Type Alopecia Areata, Totalis, and Universalis.

Alopecia areata (AA) is a common autoimmune disease with a lifetime risk of ∼2%. In AA, the immune system targets the hair follicle, resulting in clinical hair loss. The prognosis of AA is unpredictable, and currently there is no definitive treatment. Our previous whole genome expression studies identified active immune circuits in AA lesions, including common γ-chain cytokine and IFN pathways. Because these pathways are mediated through JAK kinases, we prioritized clinical exploration of small molecule JAK inhibitors. In preclinical trials in mice, tofacitinib successfully prevented AA development and reversed established disease. In our tofacitinib trial in 12 patients with moderate to severe AA, 11 patients completed a full course of treatment with minimal adverse events. Following limited response to the initial dose (5 mg b.i.d.), the dose was escalated (10 mg b.i.d.) for nonresponding subjects. Eight of 12 patients demonstrated ≥50% hair regrowth, while three patients demonstrated <50% hair regrowth, as measured by Severity in Alopecia Tool scoring. One patient demonstrated no regrowth. Gene expression profiles and Alopecia Areata Disease Activity Index scores correlated with clinical response. Our open-label studies of ruxolitinib and tofacitinib have shown dramatic clinical responses in moderate to severe AA, providing strong rationale for larger clinical trials using JAK inhibitors in AA. ClinicalTrials.gov ID NCT02299297.

Biomechanical Assessment of Hip Capsular Repair and Reconstruction Procedures Using a 6 Degrees of Freedom Robotic System.

BACKGROUND: Although acetabular labral repair has been biomechanically validated to improve stability, capsular management of the hip remains a topic of growing interest and controversy. PURPOSE: To biomechanically evaluate the effects of several arthroscopically relevant conditions of the capsule through a robotic, sequential sectioning study. STUDY DESIGN: Controlled laboratory study. METHODS: Ten human cadaveric unilateral hip specimens (mean age, 51.3 years [range, 38-65 years]) from full pelvises were used to test range of motion (ROM) for the intact capsule and for multiple capsular conditions including portal incisions, interportal capsulotomy, interportal capsulotomy repair, T-capsulotomy, T-capsulotomy repair, a large capsular defect, and capsular reconstruction. Hips were biomechanically tested using a 6 degrees of freedom robotic system to assess ROM with applied 5-N·m internal, external, abduction, and adduction rotation torques throughout hip flexion and extension. RESULTS: All capsulotomy procedures (portals, interportal capsulotomy, and T-capsulotomy) created increases in external, internal, adduction, and abduction rotations compared with the intact state throughout the full tested ROM (-10° to 90° of flexion). Reconstruction significantly reduced rotation compared with the large capsular defect state for external rotation at 15° (difference, 1.4°) and 90° (difference, 1.3°) of flexion; internal rotation at -10° (difference, 0.4°), 60° (difference, 0.9°), and 90° (difference, 1.4°) of flexion; abduction rotation at -10° (difference, 0.5°), 15° (difference, 1.1°), 30° (difference, 1.2°), 60° (difference, 0.9°), and 90° (difference, 1.0°) of flexion; and adduction rotation at 0° (difference, 0.7°), 15° (difference, 0.8°), 30° (difference, 0.3°), and 90° (difference, 0.6°) of flexion. Repair of T-capsulotomy resulted in significant reductions in rotation compared with the T-capsulotomy condition for abduction rotation at -10° (difference, 0.3°), 15° (difference, 0.9°), 30° (difference, 1.3°), 60° (difference, 1.7°), and 90° (difference, 1.5°) of flexion and for internal rotation at -10° (difference, 0.9°), 60° (difference, 1.5°), and 90° (difference, 2.6°) of flexion. Similarly, repair of interportal capsulotomy resulted in significant reductions in abduction (difference, 0.9°) and internal (difference, 1.4°) rotations compared with interportal capsulotomy at 90° of flexion. In most cases, however, after the repair procedures, ROM was still increased in comparison with the intact state. CONCLUSION: The results of this study suggest that common hip arthroscopic capsulotomy procedures can result in increases in external, internal, abduction, and adduction rotations throughout a full range (-10° to 90°) of hip flexion. However, capsular repair and reconstruction succeeded in partially reducing the increased rotational ROM caused by common capsulotomy procedures. Thus, consideration should be allotted toward capsular repair or reconstruction in cases with an increased risk of residual instability. CLINICAL RELEVANCE: Although complete restoration of joint stability may not be fully achieved at time zero, capsular repair and reconstruction may lead to improved patient outcomes by bringing hip rotational movements nearer to normal values in the immediate postoperative period, especially in cases in which extensive capsulotomy is performed.

Quantitative Anatomic Analysis of the Native Ligamentum Teres.

BACKGROUND: While recent studies have addressed the biomechanical function of the ligamentum teres and provided descriptions of ligamentum teres reconstruction techniques, its detailed quantitative anatomy remains relatively undocumented. Moreover, there is a lack of consensus in the literature regarding the number and morphology of the acetabular attachments of the ligamentum teres. PURPOSE: To provide a clinically relevant quantitative anatomic description of the native human ligamentum teres. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten human cadaveric hemipelvises, complete with femurs (mean age, 59.6 years; range, 47-65 years), were dissected free of all extra-articular soft tissues to isolate the ligamentum teres and its attachments. A coordinate measuring device was used to quantify the attachment areas and their relationships to pertinent open and arthroscopic landmarks on both the acetabulum and the femur. The clock face reference system was utilized to describe acetabular anatomy, and all anatomic relationships were described using the mean and 95% confidence intervals. RESULTS: There were 6 distinct attachments to the acetabulum and 1 to the femur. The areas of the acetabular and femoral attachment footprints of the ligamentum teres were 434 mm2 (95% CI, 320-549 mm2) and 84 mm2 (95% CI, 65-104 mm2), respectively. The 6 acetabular clock face locations were as follows: anterior attachment, 4:53 o'clock (95% CI, 4:45-5:02); posterior attachment, 6:33 o'clock (95% CI, 6:23-6:43); ischial attachment, 8:07 o'clock (95% CI, 7:47-8:26); iliac attachment, 1:49 o'clock (95% CI, 1:04-2:34); and a smaller pubic attachment that was located at 3:50 o'clock (95% CI, 3:41-4:00). The ischial attachment possessed the largest cross-sectional attachment area (127.3 mm2; 95% CI, 103.0-151.7 mm2) of all the acetabular attachments of the ligamentum teres. CONCLUSION: The most important finding of this study was that the human ligamentum teres had 6 distinct points of attachment on the acetabulum (transverse, anterior, and posterior margins of the acetabular notch and cotyloid fossa attachments: ilium, ischium, and pubis) and 1 on the femur. On the acetabulum, the anterior attachment was substantially larger than the posterior attachment and was located at a mean clock face position of 4:53 o'clock. CLINICAL RELEVANCE: These quantitative descriptions of the ligamentum teres can be used by clinicians to arthroscopically identify the attachments of the ligamentum teres, guiding arthroscopic surgical interventions designed to address ligamentum teres pathology.

Thermogenic and psychogenic recruitment of human eccrine sweat glands: Variations between glabrous and non-glabrous skin surfaces.

Human eccrine sweat-gland recruitment and secretion rates were investigated from the glabrous (volar) and non-glabrous hand surfaces during psychogenic (mental arithmetic) and thermogenic stimuli (mild hyperthermia). It was hypothesised that these treatments would activate glands from both skin surfaces, with the non-thermal stimulus increasing secretion rates primarily by recruiting more sweat glands. Ten healthy men participated in two seated, resting trials in temperate conditions (25-26°C). Trials commenced under normothermic conditions during which the first psychogenic stress was applied. That was followed by passive heating (0.5°C mean body temperature elevation) and thermal clamping, with a second cognitive challenge then applied. Sudomotor activity was evaluated from both hands, with colourimetry used to identify activated sweat glands, skin conductance to determine the onset of precursor sweating and ventilated sweat capsules to measure rates of discharged sweating. From glandular activation and sweat rate data, sweat-gland outputs were derived. These psychogenic and thermogenic stimuli activated sweat glands from both the glabrous and non-glabrous skin surfaces, with the former dominating at the glabrous skin and the latter at the non-glabrous surface. Indeed, those stimuli individually accounted for ~90% of the site-specific maximal number of activated sweat glands observed when both stimuli were simultaneously applied. During the normothermic psychological stimulation, sweating from the glabrous surface was elevated via a 185% increase in the number of activated glands within the first 60s. The hypothetical mechanism for this response may involve the serial activation of additional eccrine sweat glands during the progressive evolution of psychogenic sweating.

Multifaceted role of hair follicle dermal cells in bioengineered skins.

BACKGROUND: The method of generating bioengineered skin constructs was pioneered several decades ago; nowadays these constructs are used regularly for the treatment of severe burns and nonhealing wounds. Commonly, these constructs are comprised of skin fibroblasts within a collagen scaffold, forming the skin dermis, and stratified keratinocytes overlying this, forming the skin epidermis. In the past decade there has been a surge of interest in bioengineered skins, with researchers seeking alternative cell sources, or scaffolds, from which constructs can be established, and for more biomimetic equivalents with skin appendages. OBJECTIVES: To evaluate whether human hair follicle dermal cells can act as an alternative cell source for engineering the dermal component of engineered skin constructs. METHODS: We established in vitro skin constructs by incorporating into the collagenous dermal compartment: (i) primary interfollicular dermal fibroblasts, (ii) hair follicle dermal papilla cells or (iii) hair follicle dermal sheath cells. In vivo skins were established by mixing dermal cells and keratinocytes in chambers on top of immunologically compromised mice. RESULTS: All fibroblast subtypes were capable of supporting growth of overlying epithelial cells, both in vitro and in vivo. However, we found hair follicle dermal sheath cells to be superior to fibroblasts in their capacity to influence the establishment of a basal lamina. CONCLUSIONS: Human hair follicle dermal cells can be readily interchanged with interfollicular fibroblasts and used as an alternative cell source for establishing the dermal component of engineered skin both in vitro and in vivo.

Functional outcome after proximal humerus fracture fixation : understanding the risk factors.

The purpose is to identify risk factors of functional outcome following proximal humerus open reduction and internal fixation. Patients treated for proximal humerus fractures with open reduction and internal fixation were enrolled in a prospective data registry. Patients were evaluated for function using the Disability of the Arm, Shoulder and Hand score for 12 months and as available beyond 12 months. Univariate analyses were conducted to identify variables associated with functional outcome. Significant variables were included in a multivariate regression predicting functional outcome. Demographics and minimum of 12 month follow-up were available for 129 patients (75%). Multiple regression demonstrated postoperative complication (B=8.515 p=0.045), education level (B=-6.269p<0.0005), age (B=0.241p=0.049) and Charlson Comorbidity Index (B=6.578, p=0.001) were all significant predictors of functional outcome. Orthopaedic surgeons can use education level, comorbidities, age, and postoperative complication information to screen patients for worse outcomes, establish expectations, and guide care.

The use of ultra-low-dose CT scans for the evaluation of limb fractures: is the reduced effective dose using ct in orthopaedic injury (REDUCTION) protocol effective?

AIMS: To evaluate whether an ultra-low-dose CT protocol can diagnose selected limb fractures as well as conventional CT (C-CT). PATIENTS AND METHODS: We prospectively studied 40 consecutive patients with a limb fracture in whom a CT scan was indicated. These were scanned using an ultra-low-dose CT Reduced Effective Dose Using Computed Tomography In Orthopaedic Injury (REDUCTION) protocol. Studies from 16 selected cases were compared with 16 C-CT scans matched for age, gender and type of fracture. Studies were assessed for diagnosis and image quality. Descriptive and reliability statistics were calculated. The total effective radiation dose for each scanned site was compared. RESULTS: The mean estimated effective dose (ED) for the REDUCTION protocol was 0.03 milliSieverts (mSv) and 0.43 mSv (p < 0.005) for C-CT. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of the REDUCTION protocol to detect fractures were 0.98, 0.89, 0.98 and 0.89 respectively when two occult fractures were excluded. Inter- and intra-observer reliability for diagnosis using the REDUCTION protocol (κ = 0.75, κ = 0.71) were similar to those of C-CT (κ = 0.85, κ = 0.82). Using the REDUCTION protocol, 3D CT reconstructions were equivalent in quality and diagnostic information to those generated by C-CT (κ = 0.87, κ = 0.94). CONCLUSION: With a near 14-fold reduction in estimated ED compared with C-CT, the REDUCTION protocol reduces the amount of CT radiation substantially without significant diagnostic decay. It produces images that appear to be comparable with those of C-CT for evaluating fractures of the limbs. Cite this article: Bone Joint J 2016;98-B:1668-73.

Sex differences in genomics in lupus: girls with systemic lupus have high interferon gene expression while boys have high levels of tumour necrosis factor-related gene expression.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a chronic disease occurring up to 15 times more frequently in females than males. This bias extends to possible differences in disease flares and response to therapy. This study was initiated to investigate the differences between girls and boys with childhood-onset SLE (cSLE) at the molecular level. METHOD: We analysed the Gene Expression Omnibus National Center for Biotechnology Information (GEO NCBI) microarray data available for 88 girls and 16 boys with treatment-naïve cSLE and compared the results to those from healthy controls. Transcriptional profiles were generated using the platforms of Affymetrix U133A and U133B gene chips and Bioconductor/R programming packages were used to process and compare the data. RESULTS: Girls with cSLE overexpressed an interferon (IFN)-α signature that was absent in boys. Boys with cSLE were observed to overexpress tumour necrosis factor-related genes that were absent in girls. Both boys and girls were observed to overexpress several genes related to granulopoeisis. CONCLUSIONS: Our results suggest a potential application of genomics to differentially predict response to therapy between females and males with SLE.

Radiographic Identification of Arthroscopically Relevant Acetabular Structures.

BACKGROUND: The anatomy of the acetabulum has been described extensively in the literature, but radiographic acetabular guidelines have not been well established. This study provides a radiographic map of acetabular landmarks in the hip. PURPOSE/HYPOTHESIS: The purpose of this study was to quantify the precise radiographic location of arthroscopic landmarks around the acetabulum. The hypothesis was that their locations were reproducible despite variability in the anatomy and positioning of pelvic specimens. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten fresh-frozen cadaveric specimens were dissected, and radio-opaque hardware was placed for each landmark of interest. Anteroposterior (AP) and false-profile radiographs were obtained, and measurements were taken using a digital picture archiving and communication system. RESULTS: On AP radiographs, the direct and indirect heads of the rectus femoris were a mean 48.2 ± 4.6 mm and 44.7 ± 4.3 mm proximal to the teardrop line, respectively. The mean radiographic distance between their insertions was 5.0 ± 3.4 mm. Moreover, the anterior inferior iliac spine was a mean 11.5 ± 3.8 mm from the acetabular rim. On false-profile radiographs, the mean distance between the direct and indirect heads of the rectus femoris was 31.4 ± 6.2 mm. The mean distance between the superior margin of the anterior labral sulcus (the psoas-u) and the midpoint of the transverse acetabular ligament was 41.0 ± 5.7 mm. Additionally, the direct and indirect heads of the rectus femoris corresponded to the 2:30 and 1:30 locations on the acetabular clockface, respectively. The midpoint of the transverse acetabular ligament was located at 7 o'clock on the clockface. CONCLUSION: The most important finding of this study, determined by quantitative measurements, was that the described surgical landmarks had reliable locations on radiographs. Distances between landmarks as well as distances between landmarks and reference lines were reproducible in both AP and false-profile views. CLINICAL RELEVANCE: An understanding of how acetabular structures present on radiographs could lead to more accurate portal and hardware placement intraoperatively during arthroscopic surgery as well as better preoperative and postoperative assessments.

Radiographic Identification of Arthroscopically Relevant Proximal Femoral Structures.

BACKGROUND: Anatomic landmarks located on the proximal femur have only recently been defined, and there is a lack of radiographic guidelines for their locations presented in the literature. With the confident identification of these landmarks, radiographs could provide more assistance in preoperative evaluations, intraoperative guidance, and postoperative assessments. PURPOSE: To quantify the radiographic locations of endoscopic landmarks of the proximal femur. STUDY DESIGN: Descriptive laboratory study. METHODS: Ten cadaveric specimens were dissected, and radio-opaque hardware was placed for each landmark of interest. Radiographs were obtained and measurements recorded in anteroposterior (AP) and Dunn 45° views. RESULTS: In the AP view, the gluteus medius insertion was located a mean 12.9 ± 2.4 mm and 34.7 ± 5.1 mm from the piriformis fossa and vastus tubercle, respectively. The piriformis fossa was a mean 14.8 ± 5.9 mm and 4.9 ± 1.9 mm from the anterior and posterior tips of the greater trochanter, respectively. The anterior and posterior tips of the greater trochanter were a mean 14.8 ± 5.1 mm from each other. In the Dunn 45° view, the piriformis fossa was a mean 13.3 ± 2.0 mm, and the vastus tubercle was a mean 21.5 ± 6.0 mm, from the gluteus medius insertion. Moreover, the vastus tubercle was a mean 33.5 ± 6.4 mm from the anterior tip of the greater trochanter and 31.6 ± 8.5 mm from the posterior tip of the greater trochanter. CONCLUSION: In spite of the variation in cadaveric sizes, quantitative descriptions of endoscopic landmarks were reproducible in clinical views. CLINICAL RELEVANCE: A detailed understanding of how the described landmarks present radiographically is relevant to preoperative planning, intraoperative evaluations, and postoperative assessments.

Validation of a six degree-of-freedom robotic system for hip in vitro biomechanical testing.

Currently, there exists a need for a more thorough understanding of native hip joint kinematics to improve the understanding of pathological conditions, injury mechanisms, and surgical interventions. A biomechanical testing system able to accomplish multiple degree-of-freedom (DOF) movements is required to study the complex articulation of the hip joint. Therefore, the purpose of this study was to assess the repeatability and comparative accuracy of a 6 DOF robotic system as a testing platform for range of motion in vitro hip biomechanical analysis. Intact human cadaveric pelvises, complete with full femurs, were prepared, and a coordinate measuring machine collected measurements of pertinent femoral and pelvic bony landmarks used to define the anatomic hip axes. Passive flexion/extension path and simulated clinical exam kinematics were recorded using a 6 DOF robotic system. The results of this study demonstrate that the 6 DOF robotic system was able to identify hip passive paths in a highly repeatable manner (median RMS error of <0.1mm and <0.4°), and the robotically simulated clinical exams were consistent and repeatable (rotational RMS error ≤0.8°) in determining hip ranges of motion. Thus, a 6 DOF robotic system is a valuable and effective tool for range of motion in vitro hip biomechanical analysis.

Outcomes After Labral Repair in Patients With Femoroacetabular Impingement and Borderline Dysplasia.

PURPOSE: To determine outcomes after labral repair in patients with borderline dysplasia and femoroacetabular impingement (FAI). METHODS: Patients with dysplasia treated between June 2005 and March 2009 were identified. The study included only patients aged 18 years or older (mean, 35 years; range, 18 to 69 years) whose affected hip had a Wiberg center-edge angle of 20° to 25° and who underwent primary hip arthroscopy performed by the senior author. RESULTS: One hundred two hips (100 patients, comprising 50 women and 50 men) underwent hip arthroscopy with labral repair with correction of FAI and capsular closure. Five hips were converted to total hip arthroplasty, and 7 required revision arthroscopy. Of 95 patients (representing 100 hips, 5 of which underwent total hip arthroplasty), 80 were monitored for a minimum of 2 years. At a mean follow-up point of 40 months, the preoperative modified Harris Hip Score had improved from a mean of 63.5 points (range, 20 to 98 points) to a mean of 84.9 points (range, 45 to 100 points) by the latest follow-up (P < .001). The mean score on the Western Ontario and McMaster Universities Arthritis Index improved from 25.3 (range, 0 to 60) to 9.7 (range, 0 to 59) (P < .001). The 12-Item Short Form Health Survey Physical Component Summary score also significantly improved (from 42.5 to 50.9, P = .001), whereas the 12-Item Short Form Health Survey Mental Health Component Summary score showed an insignificant improvement (from 52.4 to 54.1). CONCLUSIONS: This study showed that FAI and labral pathology can be successfully managed using hip arthroscopy, with capsular management, in patients with borderline dysplasia. Patients showed significant improvements in outcomes and high levels of satisfaction after hip arthroscopy. The need for subsequent procedures was similar to that in patients with just FAI and labral repair. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Arthroscopic capsule reconstruction in the hip using iliotibial band allograft.

The hip capsule has been identified as an important static stabilizer of the hip joint. Despite the intrinsic bony stability of the hip socket, the capsule plays a key role in hip stability, particularly at the extremes of motion, and the iliofemoral ligament is the most important stabilizer in extension and external rotation. Patients who do not undergo capsular closure or plication may continue to complain of hip pain and dysfunction postoperatively, likely because of microinstability or muscle invagination into the capsular defect, and high-resolution magnetic resonance imaging or magnetic resonance arthrography will identify the capsular defect. Seen primarily in the revision setting, capsular defects can cause recurrent stress at the chondrolabral junction. An attempt at secondary closure can be challenging because of capsular limb adherence to the surrounding soft tissues. Therefore reconstruction may be the only possible surgical solution for this problem. We describe our new surgical technique for arthroscopic hip capsular reconstruction using iliotibial band allograft.