Initial Hip Research Articles

Is This Rapid Destructive Hip Osteoarthritis ?

Rapid destructive hip osteoarthritis is a diagnosis by exclusion. It should be differentiated from septic arthritis, osteonecrosis, neuropathic arthritis and other aetiologies causing rapid bone resorption or destruction around the hip. The present study aims to review the incidence of rapid destructive hip osteoarthritis among those patients who request total hip arthroplasty for end stage arthrosis.A retrospective review of radiographs of all patients who scheduled for total hip arthroplasty from January 2010 to March 2019 were analysed by 3 orthopaedic fellows. Of 174 hips of 146 patients, 35 hips of 29 patients were considered by at least 2 orthopaedic fellows to have rapid destructive hip osteoarthritis based on radiographic criteria of rapid joint space narrowing or rapid destruction of femoral head with or without acetabular involvement. Clinical history and physical finding, blood biochemistry, cultures and pathology with or without frozen section are reviewed.Early total hip arthroplasty, rather than routine operation in the long waiting list, is recommended for rapid destructive hip osteoarthritis to prevent technical difficulty in dealing with the bone loss or defect associated with rapid destructive hip osteoarthritis. However, one must exclude septic arthritis before proceeding to total hip arthroplasty. In clinically highly suspected cases, staged total hip arthroplasty was done despite of normal initial blood investigationsand negative hip aspiration with equivocal frozen section on table. In one such patient, the culture was initially negative, but became positive only after extended period of culture. On the other hand, rapid destruction of acetabulum requiring impaction bone grafting and acetabular augmentation for total hip arthroplasty was needed in one patient. Malignancy was suspected in another patient, but there was no evidence of malignancy or infection in the femoral head and tissue obtained by excisional arthroplasty of hip. One patient with hip pain and bilateral hip involvement was found to have Charcot joint.Rapid destruction hip osteoarthritis represents an uncommon subset of arthrosis with rapid progression. A delicate balance between correct diagnosis and timely early operation should be exercised to prevent rapid loss of bone stock making delayed total hip arthroplasty become technical difficult with possible compromised outcomes.

Pseudotumor recurrence in a post-revision total hip arthroplasty with stem neck modularity: A case report

This unique presentation of hip swelling is only the seventh reported case of pseudotumor recurrence in a non-metal-on-metal total hip arthroplasty (THA) construct. The constellation of patient symptoms and laboratory findings contradict the expected elevated serum metal ion levels associated with the formation of pseudotumor. The presentation, lab trends, and imaging findings contribute to the growing base of knowledge surrounding the effects of corrosion in arthroplasty constructs with stem-neck modularity. A 74-year-old man status post primary THA presented with left hip swelling and elevated serum metal ions five years after implantation of a modular stem-neck prosthesis. The swelling was diagnosed as pseudotumor based on laboratory trends and imaging findings and was treated with revision arthroplasty that completely resolved the initial hip swelling. The patient presented with recurrent hip swelling and recurrent pseudotumor findings on imaging in the same hip four months later. Non-operative management with ultrasound-guided hip aspiration resulted in symptom relief and resolution of the recurrent swelling. After one year of follow-up, the patient had no further recurrences of hip swelling. This case of post-revision pseudotumor recurrence elucidates attributable patient, surgical, and implant factors with a discussion of diagnostics, management, and prognosis for patients with pseudotumor in non-metal-on-metal arthroplasty constructs.

Jump-landing mechanics in patellar tendinopathy in elite youth basketballers.

Patellar tendinopathy (PT) is a leading cause of morbidity in jump-landing athletes. Landing mechanics are identified as a factor associated with PT and/or patellar tendon abnormality. This study aimed to identify key jump-landing variables associated with PT. Thirty-six junior elite basketball players (men n=18, women n=18) were recruited from a Basketball Australia development camp. Three-dimensional (3D) kinematic and ground reaction force (GRF) data during a stop-jump task were collected as well as ultrasound scans of the patellar tendons and recall history of training load data. Mixed-model factorial analyses of variance were used to determine any significant between-group differences. Of the 23 participants included for statistical analyses, 11 had normal bilateral patellar tendons (controls) and eight reported PT (currently symptomatic); however, the four participants categorized as asymptomatic with patellar tendon abnormality on diagnostic imaging were excluded from statistical analyses due to their small sample size. Athletes with PT displayed a similar knee flexion angle at initial foot-ground contact (IC) and hip extension strategy during a stop-jump horizontal landing. Despite a similar kinematic technique, athletes with PT utilized a strategy of a longer stance duration phase from IC to peak force. This strategy did not lead to those athletes with PT decreasing their peak vertical GRF nor patellar tendon force during landing but enabled these athletes to land with a lower rate of loading (control 59.2 ± 39.3 vs. PT 29.4 ± 33.7 BW.s-1). Athletes with PT still reported significantly reduced training volume (control 4.9±1.8 vs PT 1.8±1.1 sessions/wk; total training time/wk control 2.4±1.0 vs PT 1.4±1.1h/wk).

Effects of Foot Rotation on ACL Injury Risk Variables During Drop Landing

Landing is considered a “high-risk” movement for anterior cruciate ligament (ACL) injuries. Foot progression angle (FPA) during landing has been shown to influence hip, knee, and ankle mechanics. The purpose of this study was to compare five FPA conditions during drop landings between males and females. Twenty males and females were tested using five FPA conditions: self-selected, toe-in 15°, toe-in 30°, toe-out 15°, and toe-out 30°. Right hip, knee, and ankle joint kinematics and kinetics were collected using a 12-camera motion capture system and two force plates. Five successful trials were collected and compared between FPA conditions. The main effect for FPA condition was statistically different for initial contact hip flexion, hip abduction, hip internal rotation, knee flexion, knee abduction, knee external rotation, and ankle inversion angles compared to self-selected FPA at P < 0.05. Peak hip extension, hip abduction, knee adduction, knee internal rotation, ankle plantar flexion, and ankle inversion moments were also found to be statistically significant (P < 0.05). Overall, females experienced greater initial knee abduction angle (P = 0.028), hip abduction moment (P = 0.006), knee extension moment (P = 0.033), and knee internal rotation moment (P = 0.044), regardless of FPA condition. Males experienced greater initial contact hip abduction angle (P = 0.0017), regardless of FPA condition. The results suggest that landing with large toe-in FPA will increase the magnitude of ACL injury risk variables, and females demonstrated a greater magnitude in these variables compared to males. Injury prevention programs may seek to target FPA as part of training activities to avoid large FPA toe-in landings.

The Learning Curve in Hip Arthroscopy: Effect on Surgical Times in a Single-Surgeon Cohort

To quantify the effect of the learning curve in performing hip arthroscopy for femoroacetabular impingement (FAI) and labral tears on total operating room time, including times for setup, surgery, and wake up, during a single surgeon's initial hip arthroscopy procedures. A single surgeon's case list was retrospectively reviewed to identify all primary hip arthroscopy surgeries between November 1, 2018, and February 28, 2018, for the treatment of FAI and labral tears. Surgical times were recorded, including total room time; surgical time; setup time; and wake-up time. Linear regression was used to evaluate the relationship of these times relative to case number in the series. In addition, the series was divided into 3 sequential groups to further compare these times. In total, 225 patients were included in the study. The mean total room time for all cases was 155.4 minutes, 95% confidence interval ([CI] 150.9-160.0); mean surgical time was 115.6 minutes (95% CI 111.5-119.8), and mean setup time was 32.6 minutes (95% CI 31.8-33.4). Decreasing surgical time was associated with advancing number in the case series (P < .001, R2= 0.36). Decreasing total room time was accordingly associated with advancing number in the case series (P < .001, R2= 0.34). There were no significant differences in setup time and wake-up time as the case series advanced. When groups of 75 sequential cases were compared, significant decreases in surgical and total room time were noted between the first and second groups (P < .001) but not between the second and third groups (P= .52). Increasing complexity of surgeries was noted as the series advanced, including capsular closure and subspine decompression. This study supports the existence of a substantial learning curve for hip arthroscopy in the treatment of FAI and labral tears. Our findings suggest decreasing surgical time as the surgeon advances through the learning curve, with the initial 75 procedures requiring longer time to perform than subsequent cases. Hip arthroscopy is a technically demanding procedure. Understanding the long duration of the hip arthroscopy learning curve is helpful for surgeons considering the addition of hip arthroscopy to their practice.

La hanche chez l’enfant de 0 à 17 ans

In children, hip diseases are revealed by a walking disorder or limping, which requires physical examination and imaging by ultrasound, radiography and, depending on the case, MRI. The diagnoses differ according to age and the inflammatory or mechanical nature of the symptoms. Before the age of two, two diagnoses are encountered: septic arthritis (therapeutic emergency) and hip dysplasia, which must be systematically screened. After two years the most common cause of acute hip arthritis is transient hip synovitis; juvenile idiopathic arthritis may be revealed by an initial hip injury (especially in the case of spondyloarthropathies); cases of villo-nodular synovitis and osteochondromatosis are rare; bone may also be involved (recurrent multifocal osteitis, osteoid osteoma or much more rarely malignant tumor). Mechanical hip pain is more common in boys: osteochondritis (Legg-Perthes-Calvé disease) occurs between 4 and 8years of age, epiphysiolysis is observed later at around 13/14years of age in boys often overweight; it can be complicated by chondrolysis. Apophysitis in the greater trochanter, iliac spines or ischium can also cause hip pain in children aged 12 to 15years old practicing many sports.

Effects of Hip Structure Analysis Variables on Hip Fracture: A Propensity Score Matching Study.

The purpose of this retrospective study was to compare the hip structural analysis (HSA) levels of patients with those of a hip fracture group. All patients with an initial hip fracture who were older than or equal to 65 years old and admitted to our hospital between March 2018 and January 2019 were eligible for this study. During the study period, 134 hip fracture patients aged 65 years and older were admitted to the study institution, and a total of 51 hip fracture patients were ultimately assigned to the patient group. Age, sex, body mass index (BMI), skeletal muscle index (SMI), and vitamin D were matched in the two groups (hip fracture (HF) group vs. non-hip fracture group) using propensity score matching (PSM) without any statistical differences. Following propensity score matching, 51 patients in the HF group and 51 patients in the non-HF group were included in the study, respectively. Hip axis length (p = 0.031), neck-shaft angle (p = 0.043), width of intertrochanter (p = 0.005), and femur shaft (p = 0.01) were found to be significantly higher in the HF group (107.31 (mean) ± 9.55 (standard deviation, SD), 131.11 ± 5.29, 5.57 ± 0.58, and 3.05 ± 0.23, respectively) than in the non-HF group (102.07 ± 14.15, 128.85 ± 5.81, 5.29 ± 0.38, and 2.92 ± 0.23, respectively). However, cross-sectional area (CSA) of femur neck (p = 0.005) and femur shaft (p = 0.01) as well as cortical thickness (CT) of femur neck (p = 0.031) and femur shaft (p = 0.031) were found to be significantly lower in the HF group (1.93 ± 0.44, 3.18 ± 0.83, 0.11 ± 0.02, and 0.38 ± 0.09, respectively) than in the non-HF group (2.12 ± 0.46, 3.57 ± 0.78, 0.13 ± 0.03, and 0.47 ± 0.11, respectively). The HSA showed excellent sensitivity (82.4% to 90.2%). HSA is an important factor in predicting the occurrence of hip fracture. Therefore, not only should bone mineral density (BMD) be considered clinically, but it is also important to look closely at HSA for risk of hip fracture.

Clinical and Radiographic Predictors for Unsalvageable Labral Tear at the Time of Initial Hip Arthroscopic Management for Femoroacetabular Impingement

Background: The acetabular labrum plays important roles in proprioception, nociception, synovial fluid seal effect, and static and dynamic joint stability and as a shock absorber. Clinical and radiographic risk factors for unsalvageable labral tear in femoroacetabular impingement (FAI) are not well established. Purpose: To identify predictors of unsalvageable labral tear during initial hip arthroscopic management of FAI. Study Design: Case-control study; Level of evidence, 3. Methods: Patients were included who underwent primary hip arthroscopic treatment for FAI between March 2009 and March 2014. Patients were excluded who had <2-year follow-up, underwent bilateral surgery, or had a history of surgery, osteoarthritis (Tönnis grade 2 or 3), and other diagnoses, including lateral center-edge angle <25° diagnosed as developmental hip dysplasia. Patients were divided into 2 groups according to their labral condition: reconstruction and refixation. Unsalvageable labral tear was defined as any irreparable labral tear, including severe degenerative tear, frayed labrum, labral ossification, flattened labrum, and failed prior repair during surgery. Univariate and multivariate analyses identified risk factors for segmental labral reconstruction. Patient-reported outcome scores and postoperative revision rates were also assessed. Results: Twenty-five hips (18 male, 7 female) and 126 hips (65 male, 61 female) were included in the reconstruction and refixation groups, respectively. The mean ± SD ages were 52.6 ± 15.0 and 36.5 ± 16.1 years in the reconstruction and refixation groups, respectively. In the reconstruction group, the mean modified Harris Hip Score significantly improved from 67.3 ± 14.9 preoperatively to 95.0 ± 8.1 at final follow-up (P < .001), and the mean Nonarthritic Hip Score improved from 63.0 ± 18.3 preoperatively to 89.5 ± 10.1 at final follow-up (P < .001). In the refixation group, the mean modified Harris Hip Score significantly improved from 69.2 ± 18.6 preoperatively to 93.0 ± 11.2 at final follow-up (P < .001), and the mean Nonarthritic Hip Score improved from 60.7 ± 18.8 preoperatively to 88.6 ± 15.0 at final follow-up (P < .001). No significant difference was noted in patient-reported outcome scores and revision hip arthroscopy rates. The rate of conversion of total hip arthroplasty was higher in the reconstruction group than in the refixation group. Risk factors for unsalvageable labral tear were age ≥45 years (odds ratio [OR], 8.83; P < .007), body mass index ≥23.1 kg/m2 (OR, 13.05; P < .001), and vertical center anterior angle ≥36° (OR, 19.03; P < .001). Furthermore, in this study, unsalvageable labral tears were present in cases with at least 2 of the 3 risk factors. Conclusion: Age ≥45 years, body mass index ≥23.1 kg/m2, and vertical center anterior angle ≥36° are risk factors for unsalvageable labral tear at initial hip arthroscopic surgery for patients with FAI.

Value of the 'clicky hip' in selective screening for developmental dysplasia of the hip.

The aim of this study was to review the value of accepting referrals for children with 'clicky hips' in a selective screening programme for hip dysplasia. A single-centre prospective database of all referrals to the hip clinic was examined to identify indication for referrals, diagnosis, and treatment. All patients referred received a standardized ultrasound scan and clinical examination by an orthopaedic consultant. There were 5716 children referred to the orthopaedic hip clinic between 1 June 2014 and 26 September 2018. In all, 1754 children (30.1%) were referred due to 'clicky hip' with no additional risk factors or indications for ultrasound scan. A total of 123 children (7.1%) referred with 'clicky hip' and no additional risk factors or examination findings had an abnormal initial hip ultrasound, including 16 children (0.9%) with dysplastic hips. Of the 141 children who required treatment in a Pavlik harness during the study period, 23 (16%) had been referred with a 'clicky hip' and no additional risk factors or examination findings, including six children with Graf 3 or 4 hips. There is significant value in reviewing children with an isolated 'clicky hip'. Many children who require treatment are referred to the orthopaedic service as 'clicky hip' with no additional risk factors. In a pragmatic pathway with a diverse population of clinicians performing baby checks, 'clicky hip' is an important indication for referral and should not be discarded. Cite this article: Bone Joint J 2019;101-B:635-638.

Factors associated with gait outcomes in patients with traumatic lumbosacral plexus injuries.

Lumbosacral plexus injuries usually occur in patients with severe, multiple traumas requiring intensive care, affecting gait function. The purpose of the present study was to identify the initial factors associated with gait outcome in lumbosacral plexus injuries caused by traumas. We retrospectively identified 664 patients with pelvic fractures caused by trauma between 2006 and 2017. The lumbosacral plexus injuries were electrodiagnostically confirmed in 30 patients (4.5%). Demographic, injury-related, fracture-related and electrodiagnostic factors were compared between patients with long-term unassisted gait outcomes to those with assisted gait outcomes, with an average of 27months elapsing after the trauma. Eleven patients (36.7%) remained in the assisted gait group during the follow-up period. Complex pelvic trauma, rather than the severity of trauma to the entire body, was associated with a poor gait outcome. Among the various causes of injury, pedestrians struck by vehicles were associated with assisted gait outcomes. The number of anatomic locations involved in pelvic fractures, pelvic ring instability by Tile classification, and the proportion of unstable sacral fractures were higher in patients with assisted gait outcomes compared with those having unassisted gait outcomes. Weaknesses in the initial hip extensor, knee flexor, ankle dorsiflexor and ankle plantar flexor were observed significantly more often in patients with assisted gait outcomes. The Dumitru and Wilbourn's scale of the anterior and posterior sacral plexus was significantly higher in the assisted gait group. Gait outcome after lumbosacral plexus injury is associated with the range and stability of the pelvic fracture and the severity of the anterior and posterior sacral plexus injury. Poor gait outcome was associated with the severity of the trauma to the pelvis rather than that to the entire body.

Using Patient-Reported Outcomes to Predict Revision Arthroplasty Following Femoral Neck Fracture: Enhancing the Value of Clinical Registries through Data Linkage.

The aim of this study was to determine the association between patient-reported outcome measures (PROMs) six months following femoral neck fracture after a low fall and future arthroplasty, and the factors associated with this. Six-month post-fracture PROMs were collected from the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR) for patients aged >55 years who were admitted for a femoral neck fracture after a low fall between March 2007 and June 2015. These cases were linked with those registered by Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) up to October 2016. Multivariable analysis was performed using a Cox proportional hazards model to determine factors associated with future arthroplasty, including six-month PROMs. Of the 7077 hip fracture patients registered by VOTOR during the study period, 2325 met the inclusion criteria. Internal fixation being used for the initial hip fracture surgery, being younger and having no pre-injury disability were all independently associated with future revision or conversion to arthroplasty. Out of all PROMs, reporting pain and discomfort six months post-fracture was associated with a 9.5-fold increase in the risk of future arthroplasty (95% CI: 3.81, 23.67). The value of clinical registries can be enhanced via data linkage, in this case by using PROMs to predict arthroplasty following femoral neck fracture.

Short-term risk factors for a second hip fracture in a UK population

IntroductionA hip fracture carries significant morbidity and mortality—a second fracture of the contralateral hip carries even higher complications. Most second hip fractures occur within 48 months of the first. The aim of this study was to comprehensively analyse all identifiable variables that may increase the risk of a contralateral hip fracture within this time period.MethodsWe retrospectively analysed 1242 consecutive patients with hip fractures presenting to our institution. All patient-related, surgery-related and inpatient variables were collected from the index admission. We then identified patients with a subsequent contralateral hip fracture in the following 2 years. Univariate and multivariate analyses were performed to identify risk factors associated with a second fracture.ResultsA total of 66 patients (5.3%) had a contralateral hip fracture in the 2 years following initial hip fracture. Mean age at first presentation was 81 years, and mean time to second fracture was 305 days. Following multivariate analysis, the patients at highest risk of a second fracture were those with dementia, acute inpatient chest infection, urinary tract infection and multiple comorbidities as measured by the Charlson score. Discharge destination after initial fracture was not associated with the risk of a second fracture.ConclusionsWe have identified a number of discrete risk factors that are associated with a short- to medium-term risk of contralateral hip fracture that may be useful in screening for patients at risk and provide them with focused medical rehabilitation.

Supplementation of sodium butyrate to postweaned heifer diets: Effects on growth performance, nutrient digestibility, and health

The objective of this study was to determine the effect of varying levels of sodium butyrate (SB) supplementation in feed on the growth, digestibility, and health of postweaned heifers. Forty Holstein dairy heifers with a mean age of 84 d and average body weight (BW) of 100.9 ± 11.2 kg were housed in a naturally ventilated freestall barn. Heifers were blocked by birth date and randomly assigned to 1 of 4 treatments in a completely randomized block design: (1) 100 g of soybean meal carrier (control), (2) 0.25 g of SB/kg of BW plus carrier, (3) 0.50 g of SB/kg of BW plus carrier, and (4) 0.75 g of SB/kg of BW plus carrier. Carrier with or without SB was top-dressed and hand-mixed into a total mixed ration once daily. Heifers were fed to provide 10% orts. Initial BW, hip and withers heights, heart girth, and body length were measured before the start of the study and every week thereafter until the 14-wk trial was over. Blood samples were obtained and plasma urea nitrogen, plasma glucose, and whole-blood β-hydroxybutyrate concentrations were determined before the start of treatment and weekly thereafter until the conclusion of the study. Fecal samples were taken before treatment and every other week from each heifer for coccidia counts. Apparent total-tract nutrient digestibility was determined using acid detergent insoluble ash as an internal marker. Each heifer underwent this phase from d 47 until d 54 of the study. Sodium butyrate had a positive effect on average BW and overall BW gain. Feed efficiency tended to improve as SB supplementation increased. Coccidia counts were lowest in the treatment with 0.25 g of SB/kg of BW plus carrier. Sodium butyrate had no effects on skeletal growth or plasma urea nitrogen concentration. Blood glucose concentration decreased linearly and β-hydroxybutyrate increased linearly with increasing levels of SB supplementation. Sodium butyrate supplementation did not affect apparent total-tract nutrient digestibility. Sodium butyrate supplementation offers positive results in the growth performance and feed efficiency of postweaned heifers.

Assessment of Sit-to-Stand Movements Using a Single Kinect Sensor

The aim of this article is to show that the absolute measurement difference between the Kinect-based system and the marker-based system for the sit-to-stand exercise is less important provided that the difference is caused by systematic errors in the Kinect measurement. Three healthy individuals participated in this study. Marker trajectories and Kinect skeletal joint data were collected while each subject performed the sit-to-stand exercise. Three key parameters, the initial, minimum, and maximum hip angles obtained from the two systems are compared. This preliminary study shows that the Kinect-based system has good agreement with the marker-based system, and it has comparable between-trial reliability and variability to those of the marker-based system. This study shows that Kinect can be used to reliably assess the quality of the sit-to-stand exercise provided that the systematic measurement errors are compensated. This study establishes the foundation to implement a Kinect-based system to automatically monitor, assess, and provide realtime feedback to a patient who carries out the sit-to-stand exercise with or without the supervision of a clinician.

A Case Series of Occult Femoral Neck Fracture, Why Plain Radiograph is not Enough?

Background: About 10% of hip fractures are missed on initial presentation and potentially expose patients to increased morbidity and unnecessary complex surgeries. 2,3 CT-scan and MRI in the emergency settings have been proposed to avoid a misdiagnosis.3,6,7 Case Series: three cases (two female and one male patient) patients with hip pain were presented with normal x-ray on initial presentation. Further investigation using CT-scan and MRI revealed femoral neck fractures. Case 1 : A 77 years-old female presented with right hip pain after a ground-level fall. Plain radiograph was normal and the patient was discharged from emergency. One week later, her hip pain worsened and a follow up x-ray showed a displaced femoral neck fracture. The fracture then treated with bipolar hemiarthroplasty. Case 2 : An 87 years-old female presented with left hip pain after a fall in the bathroom. She was able to bear weight. Initial hip x-ray appeared normal. Further investigation with a pelvic CT scan revealed a displaced femoral neck fracture. Case 3 : A 49 years-old male presented with worsening right hip pain since more than a week. The patient was physically active and has no history of trauma or associated hip injury. Initial x-ray showed a normal hip but further imaging study using MRI revealed an undisplaced femoral neck fracture. The patient was treated conservatively as he refused to do surgery. Conclusion: Traumatic hip pain with negative plain radiograph should be followed by MRI or CT -scan to avoid misdiagnosis. Keywords : Occult hip fracture, Missed hip fracture, Femoral Neck Fracture, Elderly patient

Hip Joint Torsional Loading Before and After Cam Femoroacetabular Impingement Surgery

Background: Surgical management of cam femoroacetabular impingement (FAI) aims to preserve the native hip and restore joint function, although it is unclear how the capsulotomy, cam deformity, and capsular repair influence joint mechanics to balance functional mobility. Purpose: To examine the contributions of the capsule and cam deformity to hip joint mechanics. Using in vitro, cadaveric methods, we examined the individual effects of the surgical capsulotomy, cam resection, and capsular repair on passive range of motion and resistance of applied torque. Study Design: Descriptive laboratory study. Methods: Twelve cadaveric hips with cam deformities were skeletonized to the capsule and mounted onto a robotic testing platform. The robot positioned each intact hip in multiple testing positions: (1) extension, (2) neutral 0°, (3) flexion 30°, (4) flexion 90°, (5) flexion-adduction and internal rotation (FADIR), and (6) flexion-abduction and external rotation. Then the robot performed applicable internal and external rotations, recording the neutral path of motion until a 5-N·m of torque was reached in each rotational direction. Each hip then underwent a series of surgical stages (T-capsulotomy, cam resection, capsular repair) and was retested to reach 5 N·m of internal and external torque again after each stage. During the capsulotomy and cam resection stages, the initial intact hip’s recorded path of motion was replayed to measure changes in resisted torque. Results: Regarding changes in motion, external rotation increased substantially after capsulotomies, but internal rotation only further increased at flexion 90° (change +32%, P = .001, d = 0.58) and FADIR (change +33%, P < .001, d = 0.51) after cam resections. Capsular repair provided marginal restraint for internal rotation but restrained the external rotation compared with the capsulotomy stage. Regarding changes in torque, both internal and external torque resistance decreased after capsulotomy. Compared with the capsulotomy stage, cam resection further reduced internal torque resistance during flexion 90° (change −45%, P < .001, d = 0.98) and FADIR (change −37%, P = .003, d = 1.0), where the cam deformity accounted for 21% of the intact hip’s torsional resistance in flexion 90° and 27% in FADIR. Conclusion: Although the capsule played a predominant role in joint constraint, the cam deformity provided 21% to 27% of the intact hip’s resistance to torsional load in flexion and internal rotation. Resecting the cam deformity would remove this loading on the chondrolabral junction. Clinical Relevance: These findings are the first to quantify the contribution of the cam deformity to resisting hip joint torsional loads and thus quantify the reduced loading on the chondrolabral complex that can be achieved after cam resection.

Poorer radiological outcome after delayed diagnosis and treatment in human position in Fettweis plaster cast in 93 unstable hip joints type D, III and IV according to Graf.

PurposeIn this study the course of unstable hips after successful treatment with Fettweis plaster of Paris (POP) is examined. Special focus will be given to age at beginning of treatment and initial hip type.MethodsThe development of 93 unstable hips treated between November 2001 and April 2015 was examined. Inclusion criteria were: 1) unstable hips with successful treatment with Fettweis POP; 2) presence of two pelvic radiographs (12 to 24 months and 24 to 48 months). We analyzed: 1) the initial ultrasound hip type according to Graf; 2) the average age at first and second radiograph; 3) the Tönnis classification: normal findings (< 1 SD), slightly (1 SD to 2 SD) and severely dysplastic hips (> 2 SD).ResultsIn all, there were 14 hips type D, 41 hips type III and 38 hips type IV. Mean age of the first radiograph was 13.9 months and of the second 28.5 months. The first radiograph showed: (< 1 SD): 36, (1 SD to 2 SD): 34, (> 2 SD): 23 hips, the second radiograph: (< 1 SD): 33, (1 SD to 2 SD): 19, (> 2 SD): 30 hips. With subdivision at the start of treatment at age eight or fewer weeks 2/16 hips (12.5%) and with initiation of the treatment more than eight weeks 22/77 (26.0%) deteriorated. During the course between first and second radiograph a total of 35.7% of initial hip type D, 19.5% of type III and 23.7% of type IV deteriorated.ConclusionRadiograph controls after treatment with Fettweis POP show poorer outcome after delaying the start of treatment more than 8 weeks. These findings were independent of the initial ultrasound hip type. Regular radiograph controls of all hip types treated for unstable hips are justified to detect residual dysplasia.Level of evidence:IV

313. Outpatient Treatment and Recurrence of Prosthetic Joint Infection (PJI) in Infectious Disease (ID) Physician Office Infusion Centers (POICs): A 2-Year Retrospective Multicenter Analysis

BackgroundA significant complication of prosthetic joint replacement is the development of a PJI. Therapy includes prolonged IV antibiotics (IVAB), usually delivered in the outpatient setting. Follow-up (FU) in this population can be difficult, particularly for the treating ID physician. We report our experience treating PJI in an ID POIC.MethodsRetrospective chart review was conducted of patients (patients) with initial knee or hip PJI, who received ≥3 days of IVAB in 14 ID POICs from July 2015 to July 2017. Initial clinical success (ICS) was defined as no evidence of infection at the completion of outpatient parenteral antimicrobial therapy (OPAT), although continued oral antibiotics were allowed. Available FU patients were assessed at 6 months for recurrence and associated factors analyzed using χ2 and Fisher’s exact test.ResultsWe evaluated 171 patients (122 knees, 49 hips) with a median age of 65 years (range 31–91) and 64% male. Infection occurred within 90 days of the implant in 40% (25% within 30 days). Prostheses were retained in 109 patients (64%). 91% were hospitalized prior to OPAT for 4.7 median days, with the remainder treated from the community. The median length of OPAT was 37 days (range: 8–77). Cultures were positive in 154 patients with 122 Staphylococcus spp. pathogens (43% MSSA, 43% CoNS, 13% MRSA) in 112 patients. Most commonly prescribed IVABs were vancomycin (41%) and cefazolin (37%). ICS was achieved in 163 patients (95%), independent of prosthesis removal, with 119 (73%) continuing oral antibiotics post OPAT. Eight patients did not complete OPAT. Six-month FU to the ID physician was available for 97/163 patients completing therapy (60%). Of these, recurrence occurred in 22 patients (23%) at a median of 2.1 months (range 0.2–6). Risk factors for recurrence are noted below. Oral rifampin use with IVAB was associated with a significantly lower rate of recurrence in patients with staphylococcal PJI (P = 0.004).ConclusionThis real-world evaluation underscores the challenges of successful treatment of PJI. ICS was readily achieved (95%). High recurrence (23%) may be exaggerated by lower likelihood of FU in asymptomatic patients. Lack of improvement in 6-month cure with prosthesis removal merits additional inquiry. Although the group was small, adjunctive rifampin suggests improved outcomes in staphylococcal PJI. Disclosures B. S. Metzger, Allergan: Speaker’s Bureau, Speaker honorarium. L. J. Van Anglen, Merck & Co.: Investigator, Research grant.

Risk of subsequent fracture after prior fracture among older women

SummaryAmong 377,561 female Medicare beneficiaries who sustained a fracture, 10% had another fracture within 1 year, 18% within 2 years, and 31% within 5 years. Timely management to reduce risk of subsequent fracture is warranted following all nontraumatic fractures, including nonhip nonvertebral fractures, in older women.IntroductionPrior fracture is a strong predictor of subsequent fracture; however, postfracture treatment rates are low. Quantifying imminent (12–24 month) risk of subsequent fracture in older women may clarify the need for early postfracture management.MethodsThis retrospective cohort study used Medicare administrative claims data. Women ≥ 65 years who sustained a clinical fracture (clinical vertebral and nonvertebral fracture; index date) and were continuously enrolled for 1-year pre-index and ≥ 1-year (≥ 2 or ≥ 5 years for outcomes at those time points) post-index were included. Cumulative incidence of subsequent fracture was calculated from 30 days post-index to 1, 2, and 5 years post-index. For appendicular fractures, only those requiring hospitalization or surgical repair were counted. Death was considered a competing risk.ResultsAmong 377,561 women (210,621 and 10,969 for 2- and 5-year outcomes), cumulative risk of subsequent fracture was 10%, 18%, and 31% at 1, 2, and 5 years post-index, respectively. Among women age 65–74 years with initial clinical vertebral, hip, pelvis, femur, or clavicle fractures and all women ≥ 75 years regardless of initial fracture site (except ankle and tibia/fibula), 7–14% fractured again within 1 year depending on initial fracture site; risk rose to 15–26% within 2 years and 28–42% within 5 years. Risk of subsequent hip fracture exceeded 3% within 5 years in all women studied, except those < 75 years with an initial tibia/fibula or ankle fracture.ConclusionsWe observed a high and early risk of subsequent fracture following a broad array of initial fractures. Timely management with consideration of pharmacotherapy is warranted in older women following all fracture types evaluated.

Treatment of developmental dysplasia of the hip with the Pavlik harness in children under six months of age: indications, results and failures.

PurposeThe aim of this article is to review the current concepts in the indications, results and failure causes of the treatment of developmental dysplasia of the hip (DDH) with the Pavlik harness.Methods:The reported variables influencing the outcome in the Pavlik harness treatment were analyzed.ResultsSignificant discrepancies about the clinical and radiological outcomes, the rates of failure and complications as well as the variables influencing the treatment outcome occur in the published studies due to the heterogeneity of the data and the differences in the methods used. The overall short-, mid- or long-term success rate of the treatment ranges from 45% to 100% and it is commonly over 75%. The rate of osteonecrosis of the femoral head ranges from 1% to 30%. Age, gender, laterality, radiological or clinical severity of the initial hip pathology and parents’ compliance are the commonly reported determinants of failure of the treatment.ConclusionThe failure in treatment with the Pavlik harness is multifactorial, initial type of hip dysplasia being the most prominent followed by the treatment initiation age. This type of treatment cannot be considered as the best option in Graf IV hips (hip ultrasonography) or highly dislocated hips (plain radiography) and in infants older than three months of age, as the risk of failure and development of complications including osteonecrosis and femoral nerve palsy seem to increase in such circumstances. Large-scale, comparative studies including homogenous data are needed to answer the unsolved questions concerning indications.