The Exeter short stem was designed for patients with Dorr type A femora and short-term results are promising. The aim of this study was to evaluate the minimum five-year stem migration pattern of Exeter short stems in comparison with Exeter standard stems. In this case-control study, 25 patients (22 female) at mean age of 78 years (70 to 89) received cemented Exeter short stem (case group). Cases were selected based on Dorr type A femora and matched first by Dorr type A and then age to a control cohort of 21 patients (11 female) at mean age of 74 years (70 to 89) who received with cemented Exeter standard stems (control group). Preoperatively, all patients had primary hip osteoarthritis and no osteoporosis as confirmed by dual X-ray absorptiometry scanning. Patients were followed with radiostereometry for evaluation of stem migration (primary endpoint), evaluation of cement quality, and Oxford Hip Score. Measurements were taken preoperatively, and at three, 12, and 24 months and a minimum five-year follow-up.Aims
Methods
To clarify the mid-term results of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, combined with structural allograft bone grafting for severe hip dysplasia. We reviewed patients with severe hip dysplasia, defined as Severin IVb or V (lateral centre-edge angle (LCEA) < 0°), who underwent TOA with a structural bone allograft between 1998 and 2019. A medical chart review was conducted to extract demographic data, complications related to the osteotomy, and modified Harris Hip Score (mHHS). Radiological parameters of hip dysplasia were measured on pre- and postoperative radiographs. The cumulative probability of TOA failure (progression to Tönnis grade 3 or conversion to total hip arthroplasty) was estimated using the Kaplan–Meier product-limited method, and a multivariate Cox proportional hazard model was used to identify predictors for failure.Aims
Methods
When performing revision total hip arthroplasty using diaphyseal-engaging titanium tapered stems (TTS), the recommended 3 to 4 cm of stem-cortical diaphyseal contact may not be available. In challenging cases such as these with only 2 cm of contact, can sufficient axial stability be achieved and what is the benefit of a prophylactic cable? This study sought to determine, first, whether a prophylactic cable allows for sufficient axial stability when the contact length is 2 cm, and second, if differing TTS taper angles (2° vs 3.5°) impact these results. A biomechanical matched-pair cadaveric study was designed using six matched pairs of human fresh cadaveric femora prepared so that 2 cm of diaphyseal bone engaged with 2° (right femora) or 3.5° (left femora) TTS. Before impaction, three matched pairs received a single 100 lb-tensioned prophylactic beaded cable; the remaining three matched pairs received no cable adjuncts. Specimens underwent stepwise axial loading to 2600 N or until failure, defined as stem subsidence > 5 mm.Aims
Methods
The aims of this study were to validate the Forgotten Joint Score-12 (FJS-12) in the postoperative evaluation of periacetabular osteotomy (PAO), identify factors associated with joint awareness after PAO, and determine the FJS-12 threshold for patient-acceptable symptom state (PASS). Data from 686 patients (882 hips) with hip dysplasia who underwent transposition osteotomy of the acetabulum, a type of PAO, between 1998 and 2019 were reviewed. After screening the study included 442 patients (582 hips; response rate, 78%). Patients who completed a study questionnaire consisting of the visual analogue scale (VAS) for pain and satisfaction, FJS-12, and Hip disability and Osteoarthritis Outcome Score (HOOS) were included. The ceiling effects, internal consistency, convergent validity, and PASS thresholds of FJS-12 were investigated.Aims
Methods
Hip arthroscopy (HA) has become the treatment of choice for femoroacetabular impingement (FAI). However, less favourable outcomes following arthroscopic surgery are expected in patients with severe chondral lesions. The aim of this study was to assess the outcomes of HA in patients with FAI and associated chondral lesions, classified according to the Outerbridge system. A systematic search was performed on four databases. Studies which involved HA as the primary management of FAI and reported on chondral lesions as classified according to the Outerbridge classification were included. The study was registered on PROSPERO. Demographic data, patient-reported outcome measures (PROMs), complications, and rates of conversion to total hip arthroplasty (THA) were collected.Aims
Methods
This study reports mid-term outcomes after periacetabular osteotomy (PAO) exclusively in a borderline hip dysplasia (BHD) population to provide a contrast to published outcomes for arthroscopic surgery of the hip in BHD. We identified 42 hips in 40 patients treated between January 2009 and January 2016 with BHD defined as a lateral centre-edge angle (LCEA) of ≥ 18° but < 25°. A minimum five-year follow-up was available. Patient-reported outcomes (PROMs) including Tegner score, subjective hip value (SHV), modified Harris Hip Score (mHHS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were assessed. The following morphological parameters were evaluated: LCEA, acetabular index (AI), α angle, Tönnis staging, acetabular retroversion, femoral version, femoroepiphyseal acetabular roof index (FEAR), iliocapsularis to rectus femoris ratio (IC/RF), and labral and ligamentum teres (LT) pathology.Aims
Methods
Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis. We identified 418 hips (350 patients) with a primary diagnosis of inflammatory arthritis who underwent primary THA with HXLPE liners from January 2000 to December 2017. Of these hips, 68% had rheumatoid arthritis (n = 286), 13% ankylosing spondylitis (n = 53), 7% juvenile rheumatoid arthritis (n = 29), 6% psoriatic arthritis (n = 24), 5% systemic lupus erythematosus (n = 23), and 1% scleroderma (n = 3). Mean age was 58 years (SD 14.8), 66.3% were female (n = 277), and mean BMI was 29 kg/m2 (SD 7). Uncemented femoral components were used in 77% of cases (n = 320). Uncemented acetabular components were used in all patients. Competing risk analysis was used accounting for death. Mean follow-up was 4.5 years (2 to 18).Aims
Methods
The aims of this study were to determine if an increasing serum cobalt (Co) and/or chromium (Cr) concentration is correlated with a decreasing Harris Hip Score (HHS) and Hip disability and Osteoarthritis Outcome Score (HOOS) in patients who received the Articular Surface Replacement (ASR) hip resurfacing arthroplasty (HRA), and to evaluate the ten-year revision rate and show if sex, inclination angle, and Co level influenced the revision rate. A total of 62 patients with an ASR-HRA were included and monitored yearly postoperatively. At follow-up, serum Co and Cr levels were measured and the HHS and the HOOS were scored. In addition, preoperative patient and implant variables and the need for revision surgery were recorded. We used a linear mixed model to relate the serum Co and Cr levels to different patient-reported outcome measures (PROMs). For the survival analyses we used the Kaplan-Meier and Cox regression model.Aims
Methods
Local anatomical abnormalities vary in congenital hip disease patients. Authors often present early to mid-term total hip arthroplasty clinical outcomes using different techniques and implants randomly on patients with different types of the disease, making same conclusions difficult. We report long term outcomes (13 to 23 years) of the treatment of low and high dislocation cases (separately) with total hip arthroplasty using TM technology acetabular cups (Implex initially and then Zimmer) and short fluted conical (Zimmer) femoral stems. From 2000 to 2010, 418 congenital hip disease hip joints were treated in our department with total hip arthroplasty. According to Hartofilakidis et al's classification, 230 hips had dysplasia, 101 low dislocation, (group A) and 87 high dislocation (group B). Pre-operative and post-operative values, at regular intervals, of HHS, SF-12, WOMAC, OHS and HOOS were available for all patients. Patient, surgeon and implant related failures and complications were recorded for all patients. In all cases an attempt was made to restore hip center of rotation. In group A the average lengthening was 2.8 cm (range: 1 to 4.2) and in group B 5.7 cm (range: 4.2 to 11). In both groups, no hips were revised due to aseptic loosening of either the acetabular cup or the femoral stem. In group A, a cumulative success rate of 95.6% (95% confidence interval, 92.7% – 97.4%) and in group B a cumulative success rate of 94.8% (95% confidence interval, 92.6%–96.9%) was recorded, at 20 years, with revision for any reason as an end point. No s.s. differences were found between groups when mean values of HHS, SF-12, WOMAC and OKS were compared. Satisfactory long-term clinical outcomes can be achieved in treating different types of congenital hip disease when appropriate surgical techniques combined with “game changing” implants are used.
The purpose was to determine the lifetime risk of re-operation due to specific complications related to dual mobility using re-operation as a competing risk, excluding loosening, periprosthetic fracture, and infection. 1503 mono-block dual mobility total hip arthroplasty (DM-THAs). Defining the re-operation when anesthesia (for dislocation) and revision when the implant changed. Surgery (801 for primary, 702 for revision with 201 for recurrent dislocation and 501 for loosening) performed between 1990 and 2020 in average 81-year-old (range 50–102) patients, with 522 living patients at 10 years follow-up.
The 522 patients followed ten years or more had a 15% risk revision due to DM specific complications during their lifetime and 10% more risk associated with loosening (6%), periprosthetic fracture (2%) and infection (2%).
There is a paucity of mid-term data on modular dual-mobility (MDM) constructs versus large (≥40 mm) femoral heads (LFH) in revision total hip arthroplasties (THAs). The purpose of this study was to update our prior series at 10 years, with specific emphasis on survivorships free of re-revision for dislocation, any re-revision, and dislocation. We identified 300 revision THAs performed at a single tertiary care academic institution from 2011 to 2014. Aseptic loosening of the acetabular component (n=65), dislocation (n=59), and reimplantation as part of a two-stage exchange protocol (n=57) were the most common reasons for index revision. Dual-mobility constructs were used in 124 cases, and LFH were used in 176 cases. Mean age was 66 years, mean BMI was 31 kg/m2, and 45% were female. Mean follow-up was 7 years. The 10-year survivorship free of re-revision for dislocation was 97% in the MDM cohort and 91% in the LFH cohort with a significantly increased risk of re-revision for dislocation in the LFH cohort (HR 5.2; p=0.03). The 10-year survivorship free of any re-revision was 90% in the MDM cohort and 84% in the LFH cohort with a significantly increased risk of any re-revision in the LFH cohort (HR 2.5; p=0.04). The 10-year survivorship free of any dislocation was 92% in the MDM cohort and 87% in the LFH cohort. There was a trend towards an increased risk of any dislocation in the LFH cohort (HR 2.3; p=0.06). In this head-to-head comparison, revision THAs using MDM constructs had a significantly lower risk of re-revision for dislocation compared to LFH at 10 years. In addition, there was a trend towards lower risk of any dislocation. Level of Evidence: IV
Acetabular retroversion (ARV) is a cause of femoroacetabular impingement leading to hip pain and reduced range of motion. We aimed to describe the radiological criteria used for diagnosing ARV in the literature and report on the outcomes of periacetabular osteotomy (PAO) and hip arthroscopy (HA) in its management. A systematic review using PRISMA guidelines was conducted on the MEDLINE, CINAHL, EMBASE, COCHRANE database in December 2022. English-language studies reporting outcomes of PAO, or open or arthroscopic interventions for ARV were included. From an initial 4203 studies, 21 non-randomised studies met the inclusion criteria. Eleven studies evaluated HA for ARV, with average follow-up ranging from 1 to 5 years, for a cumulative number of 996 patients. Only 3/11 studies identified ARV using AP standardized pelvic radiographs. The most frequent signs describing ARV identified were: Ischial Spine Sign (98% of patients), Posterior Wall Sign (PWS, 94%) and Crossover Sign (COS, 64%); with mean Acetabular Retroversion Index (ARI) ranging from 33% to 35%. 39% of HA patients had all three radiographic signs. Clinically significant outcomes were reached by 33–78% of patients. Eight studies evaluated PAO for ARV, with a follow-up ranging from 2 to 10 years, for a cumulative number of 379 patients. Five of the eight studies identified ARV using standardized radiographs. ISS, COS and PWS were positive in 54%, 97% and 81% of patients, respectively with 52% of PAO patients having all three radiographic signs. Mean ARI ranged from 36–41%. Clinically significant results were reported in 71%–78% of patients. The diagnostic criteria for ARV is poorly defined in the literature, and the quality of evidence is low. Studies on HA are more likely to have used lenient diagnostic criteria. It remains difficult to recommend which cases maybe more suitable for treatment by HA rather than PAO.
Acetabular component positioning is commonly referenced with the pelvis in the supine position in direct anterior approach THA. Changes in pelvic tilt (PT) from the pre-operative supine to the post-operative standing positions have not been well investigated and may have relevance to optimal acetabular component targeting for reduced risk of impingement and instability. The aims of this study were therefore to determine the change in PT that occurs from pre-operative supine to post-operative standing, and whether any factors are associated with significant changes in tilt ≥13° in posterior direction. 13° in a posterior direction was chosen as that amount of posterior rotation creates an increase in functional anteversion of the acetabular component of 10°. 1097 THA patients with pre-operative supine CT and standing lateral radiographic imaging and 1 year post-operative standing lateral radiographs (interquartile range 12–13 months) were reviewed. Pre-operative supine PT was measured from CT as the angle between the anterior pelvic plane (APP) and the horizontal plane of the CT device. Standing PT was measured on standing lateral x-rays as the angle between the APP and the vertical line. Patients with ≥13° change from supine pre-op to standing post-op (corresponding to a 10° change in cup anteversion) were grouped and compared to those with a <13° change using unpaired student's t-tests. Mean pre-operative supine PT (3.8±6.0°) was significantly different from mean post-operative standing PT (−3.5±7.1°, p<0.001), ie mean change of −7.3±4.6°. 10.4% (114/1097) of patients had posterior PT changes ≥13° supine pre-op to standing post-op. A significant number of patients, ie 1 in 10, undergo a clinically significant change in PT and functional anteversion from supine pre-op to standing post-op. Surgeons should be aware of these changes when planning component placement in THA.
Elevated blood cobalt secondary to metal-on-metal (MoM) hip arthroplasties has been shown to be a risk factor for developing cardiovascular complications including cardiomyopathy. Published case reports document cardiomyopathy in patients with blood cobalt levels as low as 13µg/l. Clinical studies have found conflicting evidence of cobalt-induced cardiomyopathy in patients with MoM hips. The extent of cardiovascular injury, measured by global longitudinal strain (GLS), in patients with elevated blood cobalt levels has not previously been examined. Sixteen patients with prospectively collected blood cobalt ion levels above 13µg/l were identified and matched with eight patients awaiting hip arthroplasty with no history of cobalt implants. Patients underwent echocardiogram assessment including GLS. Patients with MoM hip arthroplasties had a mean blood cobalt level of 29µg/l compared to 0.01µg/l in the control group. There was no difference or correlation in EF, left ventricular (LV) end systolic dimension, LV end diastolic dimension, fractional shortening, ventricular wall thickness or E/e’ ratio. However, GLS was significantly reduced in patients with MoM hip arthroplasties compared to those without (−15.2% v −18%, (MoM v control) p= 0.0125). Pearson correlation demonstrated that GLS is significantly correlated with blood cobalt level (r= 0.8742, p=0.0009). For the first time, this study has demonstrated reduced cardiac function in the presence of normal EF as assessed by GLS in patients with elevated cobalt above 13µg/l. As GLS is a more sensitive measure of systolic function than EF, routine echocardiogram assessment including GLS should be performed in all patients with MoM hip arthroplasties and elevated blood cobalt.
Both total joint arthroplasty (TJA) and Alzheimer's Disease (AD) are prevalent in elderly populations. It is the goal of this study to determine if the presence of implant metals originating from TJA correlates with the onset with higher implant metal content in the brain and AD pathology. Tissue samples from four brain regions of 701 (229 with TJA) participants from an ongoing longitudinal cohort study (Rush Memory and Aging Project) was analyzed including the inferior-temporal-cortex (ITC), which is associated with early onset of AD. Implant metal (Co, Cr, Mo, Ti, Al) content was determined by ICP-MS. Comparisons were conducted between the no-TJA-group and a TJA group. Due to the higher likelihood of Co release the TJA group was further differentiated in a THA (N=146) and a TKA/TSA (N=83) group. Diffuse and neuritic amyloid plaques and phosphorylated tau were assessed and summarized as standard measures of AD pathology. We used separate linear regression models adjusted for age, sex, education, and APOɛ4-status for the associations of all metals (log-transformed) with global AD pathology, amyloid plaques, and phosphorylated tau. The THA group had higher cobalt content across all brain regions (p=0.003) and within the ITC (p=0.051) compared to the no-TJA group, whereas the TKA/TSA group did not. Across all tissue samples, Co was associated with higher amyloid load (β=0.35, p=0.027), phosphorylated tau (β=0.47, p=0.011), and global AD pathology (β=0.19, 0.0004) in the ITC. The presence of TJA itself was not associated with AD pathology. We showed that only Co content was higher within the ITC in persons with THA. We found among all tested metals that Co was consistently associated with AD pathology. Although we found an association of cobalt with AD pathology, the cross-sectional nature of this study does not allow the determination of cause and effect.
To investigate whether anterior pelvic plane-pelvic tilt (APP-PT) is associated with distinct hip pathomorphologies, we asked: (1) Is there a difference in APP-PT between symptomatic young patients eligible for joint preservation surgery and an asymptomatic control group? (2) Does APP-PT vary between distinct acetabular and femoral pathomorphologies? (3) Does APP-PT differ in symptomatic hips based on demographic factors? IRB-approved, single-center, retrospective, case-control, comparative study in 388 symptomatic hips (357) patients (mean age 26 ± 2 years [range 23 to 29], 50% females) that presented to our tertiary center for joint preservation over a five year-period. Patients were allocated to 12 different morphologic subgroups. The overall study group was compared to a control group of 20 asymptomatic hips (20 patients). APP-PT was assessed in all patients based on AP pelvis X-rays using the validated HipRecon software. Values between overall and control group were compared using an independent samples t-test. Multiple regression analysis was performed to examine the influences of diagnoses and demographic factors on APP-PT. Minimal clinically important difference (MCID) of APP-PT was defined as >1 standard deviation. No significant differences in APP-PT between the control group and overall group (1.1 ± 3.0° [−4.9 to 5.9] vs 1.8 ± 3.4° [−6.9 to 13.2], p = 0.323) were observed. Acetabular retroversion and overcoverage groups showed higher APP-PT compared to the control group (both p < 0.05) and were the only diagnoses with significant influence on APP-PT in the stepwise multiple regression analysis. However, all observed differences were below the MCID. Demographic factors age, gender, height, weight and BMI showed no influence on APP-PT. APP-PT across different hip pathomorphologies showed no clinically significant variation. It does not appear to be a relevant contributing factor in the evaluation of young patients eligible for hip preservation surgery.
To quantify the acetabular coverage of the femoral head, Lequesne's vertical-center-anterior edge (VCA) angle is used on the false profile view. Lateral coverage is determined by Wiberg's lateral-center-edge (LCE) angle on an ap pelvic view. The delimitation of the weightbearing area is defined by the end of the subchondral sclerosis line for both views. To our knowledge the exact anatomic location of the points used for measurement on the acetabular rim are not known. Six hips from three cadaver pelvises (3 male and 3 female) were investigated. The anterior and lateral points of interested were identified radiographically using fluoroscopy and marked with 1mm ceramic bullets. Standard false profile views and ap pelvic views in neutral inclination and rotation were taken to check the correct location of the ceramic bullets. A CT of each pelvis was made to locate the ceramic bullets and to define the exact anatomic location of the measurement points on the o'clock position. 6 o‘clock was defined as the midpoint between anteroinferior and the posteroinferior rim edges. Values were normalized for a right hip. The mean clockface location for the VCA was 1:33 (range, 1:15 to 1:40) and for the LCE 0:38 (range, 0:20 to 0:50). The LCEA is slightly anterior to the 12 o'clock position and remains useful to quantify the lateral coverage. Surprisingly, the point used for measuring the VCA is only about 30° (1h) anterior of the point used for measuring the LCEA. Its value for determining anterior cover has to be questioned. The discrepancy to other studies in the literature is because this study identifies and measures the end of the weight bearing zone, and not the border of the bony acetabulum.
Injury of the lateral femoral cutaneous nerve (LFCN) is one of the known complications after periacetabular osteotomy (PAO) using anterior approach. We previously reported that the incidence of LFCN injury was 48% at 1 year after PAO. However, there was no study examining the sequential changes of LFCN injury status. In this study, we performed a prospective over 3-year follow-up study as to the incidence of LFCN injury as well as its clinical outcomes. This study included 40 consecutive hips in 40 patients (3 males and 37 females) who underwent PAO from May 2016 to July 2018. The mean age at surgery was 36.7 years (17 to 60). The mean observation period was 47.3 months (36 to 69). The incidence and severity of LFCN injury was evaluated, while clinical scores, including the Harris Hip Score (HHS), Short-Form 36 Health Survey (SF-36), and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ), were also investigated. At 3 years after PAO, LFCN injury was observed in 13 of 40 (33%) patients, in which 7 patients who had a symptom at 1 year have completely recovered. There was no significant difference in the HHS and SF-36 between patients with and without LFCN injury at 3 years. Regarding the JHEQ, a significant difference was recognized in the patient satisfaction and mental score between patients with and without LFCN injury, but there were no significant differences in the other clinical scores. The incidence of LFCN injury gradually decreased to 33% at 3 years after CPO. LFCN injury did not influence the clinician-reported outcome, while it had a negative impact on patient satisfaction and mental score based on the patient-reported outcome.
Periacetabular osteotomy (PAO) is the preferred treatment for symptomatic acetabular dysplasia in adolescents and young adults. There remains a lack of consensus regarding whether intra-articular work such as labral repair or improvement of femoral offset should be performed at the time of PAO or addressed subsequent to PAO if symptoms warrant. The purpose was to determine the rate of subsequent hip arthroscopy (HA) in a contemporary PAO cohort with no intra-articular work performed at the time of PAO. From June 2012 to March 2022, 368 rectus sparing PAOs were performed and followed for a minimum of one year (mean 5.9 years). The average age was 24 (range 14–46) and 89% were female. Patients were evaluated at last follow-up for patient-reported outcomes (PROMs). Clinical records were reviewed for complications or subsequent surgery. Radiographs were reviewed for the following acetabular parameters: LCEA, ACEA, AI, and the alpha-angle (AA). Patients were cross-referenced from the two largest hospital systems in our area to determine if subsequent HA was performed. Descriptive statistics were used to analyze risk factors for HA. 16 hips (15 patients) (4.4%) underwent subsequent HA with labral repair and femoral osteochondroplasty most common. For those with a minimum of two years of follow-up, 5.3% underwent subsequent HA. No hips underwent THA; one revision PAO was performed. 14 hips experienced a complication and 99 underwent hardware removal. All PROMs improved significantly post-operatively. Radiographically 80% of hips were in goal for acetabular correction parameters with no significant differences between those who underwent subsequent HA and those who did not. Rectus sparing PAO is associated with a low rate of subsequent HA for intra-articular pathology at 5-year follow-up. Acetabular correction alone may be sufficient as the primary intervention for the majority of patients with symptomatic acetabular dysplasia.
Oxidized zirconium (Oxinium) and highly cross-linked polyethylene (HXLPE) were developed with the purpose of minimizing wear, and subsequent osteolysis, in Total Hip Arthroplasty (THA). However, few articles have been published on long-term results of Oxinium on highly cross-linked polyethylene. The purpose of this investigation is to report minimum 10-year HXLPE wear rates and the clinical outcome of patients in this group and compare this population to a control group of cobalt chrome and ceramic. One hundred forty THAs were performed for 123 patients using an Oxinium head with an HXLPE liner. Ninety-seven had 10 years of clinical follow-up (avg. 14.5). Harris Hip Scores (HHS) were collected preoperatively and at the most recent follow-up. Radiographs of 85 hips were available for a minimum 10-year follow-up (avg. 14.5) and used to calculate wear using PolyWare software. Control groups of cobalt chrome and ceramic articulation on HXLPE with a minimum 10-year follow-up were studied. Clinical follow-up of the Oxinium group showed a statistical improvement compared to preoperative and was similar to the control group of patients. Radiographic evaluation found the linear and volumetric wear rates for the Oxinium group of 0.03 mm/year (range 0.00–0.08) and 3.46 mm3/year (range 1.0 to 15.0) respectively. There was no statistically significant difference in linear or volumetric wear rate between the groups (P-value 0.92 and 0.55 respectively). None of these patients underwent revision of their hip for any reason. Oxinium on highly cross-linked polyethylene has performed exceptionally with wear rates comparable to those of cobalt chrome or ceramic on HXLPE.
