Life Course Epidemiology of Hip Osteoarthritis in Japan: A Multicenter, Cross-Sectional Study.

BACKGROUND: The incidence of developmental dysplasia of the hip (DDH) in Japanese newborns has reduced drastically following a primary prevention campaign initiated around 1972 to 1973; this perinatal education campaign promoted maintaining the hips of newborns in the naturally flexed-leg position. The purpose of the present study was to describe the life course epidemiology of hip osteoarthritis (OA) in adolescent and adult patients and to assess its association with exposure to the primary prevention campaign for DDH. METHODS: We included new patients with hip OA diagnosed from January 1, 2022, to December 31, 2022, at 12 core hospitals (8 special-function hospitals and 4 regional medical care support hospitals). The trend in the percentage of hips with a history of DDH treatment in childhood was estimated with use of a centered moving average using the birth year of the patient. We compared the prevalence of severe subluxation (Crowe type II, III, or IV) between patients with secondary hip OA due to hip dysplasia who were born in or before 1972 and those who were born in or after 1973. RESULTS: Overall, 1,095 patients (1,381 hips) were included. The mean age at the time of the survey was 63.5 years (range, 15 to 95 years). A total of 795 patients (1,019 hips; 73.8% of hips) were diagnosed with secondary OA due to hip dysplasia. Approximately 13% to 15% of hips among patients born from 1963 to 1972 had a history of DDH treatment in childhood; however, the percentage decreased among patients born in or after 1973. The prevalence of severe subluxation (Crowe type II, III, or IV) among patients born in or after 1973 was 2.4%, which was significantly less than that among patients born in or before 1972 (11.1%; odds ratio, 0.20; p < 0.001). CONCLUSIONS: As of 2022, secondary hip OA due to hip dysplasia is still responsible for most new cases of adolescent and adult hip OA seen in core hospitals in Japan. However, the perinatal education campaign initiated 50 years ago, which utilized a population approach and advocated for maintaining the hips of newborns in the naturally flexed-leg position, may have improved the environmental factors of DDH, as indicated by the apparently reduced need for treatment of DDH in childhood and the associated severe subluxation. This may result in a reduced need for challenging hip surgery later in life. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Time elapsed from definitive diagnosis to surgery for osteonecrosis of the femoral head: a nationwide observational study in Japan.

OBJECTIVES: This study documents the time elapsed from the diagnosis of osteonecrosis of the femoral head (ONFH) to surgery, exploring the factors that influence ONFH severity. DESIGN: Retrospective observational study of a nationwide database. SETTING: The Kaplan-Meier method with log-rank tests was applied to examine the period from definitive diagnosis of ONFH to surgery using any surgery as the end point. For bilateral cases, the date of the first surgery was the endpoint. PARTICIPANTS: This study included 2074 ONFH cases registered in 34 university hospitals and highly specialised hospitals of the multicentre sentinel monitoring system of the Japanese Investigation Committee between 1997 and 2018. MAIN OUTCOME MEASURE: The primary outcome was the time from diagnosis to surgery. The secondary outcome was the proportion of subjects remaining without surgery at 3, 6 and 9 months, and at 1, 2 and 5 years after diagnosis. RESULTS: The median time to surgery was 9 months (IQR 4-22 months) after diagnosis of ONFH. The time to surgery was significantly shorter in the alcohol alone group and the combined corticosteroid and alcohol group than in the corticosteroid alone group (p=0.018 and p<0.001, respectively), in early stage ONFH with no or mild joint destruction (stages II and III, p<0.001), and with joint preserving surgery (p<0.001). The proportion without surgery was 75.8% at 3 months, 59.6% at 6 months, 48.2% at 9 months, 40.5% at 1 year, 22.2% at 2 years and 8.3% at 5 years. CONCLUSION: ONFH has been considered to be an intractable disease that often requires surgical treatment, but the fact that surgery was performed in more than half of the patients within 9 months from diagnosis suggests severe disease with a significant clinical impact. TRIAL REGISTRATION NUMBER: Chiba University ID1049.

Hip-sacroiliac joint-spine syndrome in total hip arthroplasty patients.

This study is designed to compare the extent of sacroiliac joint (SIJ) degeneration at total hip arthroplasty (THA) for two pathologies: osteoarthritis of the hip (OA) and osteonecrosis of the femoral head (ON). We also assessed the prevalence of SIJ degeneration in patients with lumbar spondylolisthesis or degenerative scoliosis. A total of 138 hips from 138 patients (69 OA and 69 ON) were assessed in this study, including 66 hips affected by OA secondary to developmental dysplasia of the hip. The degenerative changes in the SIJ and lumbar spine were evaluated prior to THA using radiographs and computed tomography (CT) scans, showing 9 instances of spondylolisthesis and 38 of degenerative scoliosis. The OA group exhibited longer duration from onset to surgery than the ON group. The OA group also included more cases with significant pelvic obliquity (3 degrees or more) and with significant increases in SIJ sclerosis and irregularities. Patients with lumbar spondylolisthesis or degenerative scoliosis were significantly more likely to have SIJ irregularities. The prevalence of SIJ degeneration was higher in cases of THA for OA than for ON. This study also suggests the possibility of Hip-SIJ-Spine syndrome in THA patients with OA.

A Case of Axillary Web Syndrome Caused by Venous Blood Sampling.

Axillary web syndrome (AWS) occurs after breast cancer surgery, sentinel lymph node dissection, or sentinel lymph node biopsy. Here, cord-like structures from the axilla to the forearm limit the range of motion of the shoulder joint and cause pain. Although the etiology is unknown, AWS has been attributed to the blockage of normal lymphatic flow. Here, we report a novel case of AWS after venous blood sampling in a patient. A healthy, 31-year-old male patient experienced pain with a limited range of motion of the shoulder joint the day after venous blood was collected from the left upper extremity for a medical checkup, and he presented to an orthopedic outpatient clinic on the day. Palpation of the axillary region disclosed a cord-like structure in the axillary region of the shoulder joint during abduction, and the patient was diagnosed with AWS. The cord-like structure was noted to be a hypoechogenic luminal structure on ultrasound (US) examination of the axilla, extending from the axilla to below the ulnar cutaneous vein from which the blood was drawn. In patients with pain and a limited range of motion of the shoulder joint, only the shoulder joint is examined during an orthopedic examination. It is important to obtain appropriate physical findings for possible AWS.

Comparative Study of Highly Cross-Linked Polyethylene Liner Wear by Hip Center Location Using Elevated Hip Center Technique in Crowe I to III Hip Dysplasia: Outcomes for a Minimum of Eighteen Years of Follow-Up.

BACKGROUND: The literature has reported that supero-lateralization of the femoral head increases the rates of aseptic loosening and prosthesis revision. However, there are few reports on the influence of different hip center positions on liner wear with more than a 15-year follow-up period. METHODS: From April 2000 to August 2003, 91 patients underwent 108 total hip arthroplasties using a highly cross-linked polyethylene liner combined with zirconia femoral head and cup components. Pelvic radiographs were used to assess the vertical and horizontal distances to the center of the hip and the amount of liner wear. Mean patient age at the time of surgery was 54 years (range, 33 to 73), and mean follow-up duration was 19 years (range, 18 to 21). RESULTS: Average liner wear was 0.221 mm, with average annual wear of 0.012 mm/year. Mean vertical and horizontal distances for the hip center were 24.9 and 31.8 mm, respectively. There was no difference in linear wear between patients who had different hip center heights (<20, 20 to 30, and >30 mm), and quadrant partitioning showed no differences across the 4 quadrant zones. CONCLUSION: At a minimum of 18 years of follow-up in patients having developmental dysplasia of the hip who had different Crowe subtypes and different hip centers, elevated hip center and uncemented fixation techniques using a highly cross-linked polyethylene on ceramic components were associated with very low wear rates and excellent functional scores.

Collarless Polished Tapered Stems of Identical Shape Provide Differing Outcomes for Stainless Steel and Cobalt Chrome: A Biomechanical Study.

Cemented polished tapered femoral stems (PTS) made of cobalt-chrome alloy (CoCr) are a known risk factor for periprosthetic fracture (PPF). The mechanical differences between CoCr-PTS and stainless-steel (SUS) PTS were investigated. CoCr stems having the same shape and surface roughness as the SUS Exeter® stem were manufactured and dynamic loading tests were performed on three each. Stem subsidence and the compressive force at the bone-cement interface were recorded. Tantalum balls were injected into the cement, and their movement was tracked to indicate cement movement. Stem motions in the cement were greater for the CoCr stems than for the SUS stems. In addition, although we found a significant positive correlation between stem subsidence and compressive force in all stems, CoCr stems generated a compressive force over three times higher than SUS stems at the bone-cement interface with the same stem subsidence (p < 0.01). The final stem subsidence amount and final force were greater in the CoCr group (p < 0.01), and the ratio of tantalum ball vertical distance to stem subsidence was significantly smaller for CoCr than for SUS (p < 0.01). CoCr stems appear to move more easily in cement than SUS stems, which might contribute to the increased occurrence of PPF with the use of CoCr-PTS.

Synovial Fluid Derived from Human Knee Osteoarthritis Increases the Viability of Human Adipose-Derived Stem Cells through Upregulation of FOSL1.

Knee osteoarthritis (Knee OA) is an irreversible condition that causes bone deformity and degeneration of the articular cartilage that comprises the joints, resulting in chronic pain and movement disorders. The administration of cultured adipose-derived stem cells (ADSCs) into the knee joint cavity improves the clinical symptoms of Knee OA; however, the effect of synovial fluid (SF) filling the joint cavity on the injected ADSCs remains unclear. In this study, we investigated the effect of adding SF from Knee OA patients to cultured ADSCs prepared for therapeutic use in an environment that mimics the joint cavity. An increase in the viability of ADSCs was observed following the addition of SF. Gene expression profiling of SF-treated ADSCs using DNA microarrays revealed changes in several genes involved in cell survival. Of these genes, we focused on FOSL1, which is involved in the therapeutic effect of ADSCs and the survival and proliferation of cancer stem cells. We confirmed the upregulation of FOSL1 mRNA and protein expression using RT-PCR and western blot analysis, respectively. Next, we knocked down FOSL1 in ADSCs using siRNA and observed a decrease in cell viability, indicating the involvement of FOSL1 in the survival of ADSCs. Interestingly, in the knockdown cells, ADSC viability was also decreased by SF exposure. These results suggest that SF enhances cell viability by upregulating FOSL1 expression in ADSCs. For therapy using cultured ADSCs, the therapeutic effect of ADSCs may be further enhanced if an environment more conducive to the upregulation of FOSL1 expression in ADSCs can be established.

Angular changes in pelvic tilt and cup orientation at a minimum of eighteen years after primary total hip arthroplasty with an uncemented cup.

BACKGROUND: Changes in pelvic tilt angle (PTA) and cup orientation have been reported in patients after total hip arthroplasty, but the current literature generally has a brief follow-up period. This study will be the first to report PTA and cup orientation changes in the supine position for a minimum 18 years after total hip arthroplasty (THA) and investigate the factors associated with pelvic tilt and cup orientation changes. METHODS: In this study, 101 patients (120 hips) who underwent THA were retrospectively analyzed. The aims of our study were to evaluate the PTA and cup orientation change over 18 years after THA to assess differential PTA, cup inclination, and anteversion. We also investigated whether factors such as gender, body mass index, and age have any influence on PTA and cup orientation after THA. RESULTS: Patients showed a significant incremental change in PTA pre-operatively, immediately post-operatively, and at final follow-up. Cup orientation increased significantly at the final follow-up compared to the immediate post-operative period. Gender subgroup analysis showed that PTA was significantly greater in females than in males at the final follow-up (p = 0.025). Age subgroup analysis showed that PTA was significantly greater in the over 60 years group than in the other groups. CONCLUSION: Our patients showed significant changes in PTA and cup orientation at a minimum 18 years after surgery, especially in females over 60 years. Female patients over 60 are a risk factor after THA.

Does the Dual Mobility Cup Reduce Dislocation After Primary Total Hip Arthroplasty in Elderly Patients at High Risk of Dislocation?

OBJECTIVE: The dual mobility cup (DMC) is designed to extend the longevity of the prosthesis by improving stability, enhancing the range of motion, and decreasing impingement without increasing wear. We hypothesized that DMC would reduce the risk of dislocation in elderly patients. This study aimed to investigate the clinical and radiographic outcomes of DMC-total hip arthroplasty (THA) in elderly patients at high risk of dislocation. METHODS: From June 2016 to March 2020, 94 patients with a mean age of 77.7 years (97 hips) who underwent a posterolateral approach for DMC-THA in our department were followed up for at least one year. Preoperative and postoperative pelvic tilt angles (PTA) and DMC orientation were prospectively collected for all patients. Intraoperative and postoperative complications were recorded. A parametric test was used for normal distribution, and a non-parametric test was used for non-normal distribution. RESULTS: Abduction and anteversion angles of the cup were 42.4 and 18.0° in the supine position immediately postoperative. The average PTA for patients in the supine and standing positions were 26.5 and 34.5°, respectively. When moving from the supine to the standing position, patients experienced a mean posterior pelvic tilt of 9°. No intraoperative acetabular-related complications were recorded. Postoperative complications included early infection in one patient (1.0%) and dislocation in one patient (1.0%). CONCLUSION: Our study demonstrates that DMC-THA provides satisfactory short-term outcomes in elderly patients at a high risk of dislocation, regardless of the change in PTA resulting from postural transition.

Current Research on Subchondral Insufficiency Fracture of the Femoral Head.

Subchondral insufficiency fracture (SIF) of the femoral head is one of the predominant etiologies of rapidly progressive osteoarthritis of the hip (RPOH). SIF is a rare disease that causes acute pain in the hip joint. It is most frequently found in elderly women with osteoporosis. It is often underdiagnosed or misdiagnosed as osteonecrosis of the femoral head. SIF is currently a well-established cause of RPOH; however, the deeper etiology of SIF is not clear. Good clinical outcomes have been reported for hip preservation therapy and hip replacement. SIF is not obvious radiologically in the early stage, and a T1-weighted magnetic resonance imaging shows a discontinuous low-intensity band under the articular cartilage convex to the articular surface as its characteristic manifestation. Some patients will lose the opportunity to preserve the hip joint due to symptoms such as progressive joint space narrowing and subchondral collapse within a very short period. Patients with progressive hip space narrowing and subchondral collapse on X-ray should be converted to total hip arthroplasty. Based on the characteristics of the disease, surgeons need to master the clinical and radiological characteristics of SIF and strive for early diagnosis and treatment.

A patient-cohort study of numerical analysis on sacroiliac joint stress distribution in pre- and post-operative hip dysplasia.

In acetabular dysplasia, the cartilaginous roof on the acetabular side does not fully cover the femoral head, which may lead to abnormal stress distribution in both the femoral head and pelvis. These stress changes may have implications to the adjacent sacroiliac joint (SIJ). The SIJ has a minimal range of motion and is closely coupled to the adjacent spine and pelvis. In consequence, the SIJ may react sensitively to changes in stress distribution at the acetabulum, with hypermobility-induced pain. The purpose of this study was to investigate the stress distribution of the SIJ in acetabular dysplasia, and to gain insight into the cause and mechanisms of hypermobility-induced pain at the SIJ. Finite element models of pre- and postoperative pelves of four patients with acetabular dysplasia were created and analyzed in double leg standing positions. The preoperative models were relatively inflare, the sacral nutation movement, SIJ cartilage equivalent stress, and the load on the surrounding ligaments decreased with increased posterior acetabular coverage. Acetabular morphology was shown to affect the SIJ, and improvement of the posterior acetabular coverage may help normalize load transmission of the pelvis and thus improve the stress environment of the SIJ in acetabular dysplasia.

Spherical Periacetabular Osteotomy.

Various techniques for periacetabular osteotomy have been reported to prevent the progression of osteoarthritis in dysplastic hips1-5. Bernese periacetabular osteotomy, which involves the use of an anterior approach, is widely performed throughout the world because it offers preservation of the blood supply to the bone fragment and lateral pelvic muscles. However, Bernese periacetabular osteotomy has potential complications, such as nonunion at the osteotomy site, postoperative fracture, nonunion of the pubis and ischium, and damage to the main trunk of the obturator artery. Spherical periacetabular osteotomy (SPO) has been developed to resolve some of disadvantages of Bernese periacetabular osteotomy6. Although SPO involves some technical difficulty, the procedure is safe when performed with use of appropriate preoperative 3-dimensional planning and surgical technique. Description: Preoperative 3-dimensional planning is utilized to decide the radius of the curved osteotome, locations of the reference points for the osteotomy line, and depth of the bone groove at the teardrop area. The pelvic positioning is arranged fluoroscopically to match the neutral position based on preoperative planning. A 7-cm incision is made along the medial margin of the iliac crest. An anterior iliac crest osteotomy of 4.5 cm (length) × 1 cm (medial wedge-shaped) is performed. The operative field is maintained with aluminum retractors. The osteotomy line is completed by connecting the preoperatively planned reference points on the inner cortex of the ilium. The bone groove is made along the osteotomy line with use of a high-speed burr. A blunt osteotome is inserted into the bone groove at the teardrop area until it reaches the preoperatively planned depth. The blunt osteotome makes a pathway for the curved osteotome without breaking the quadrilateral surface (QLS) or perforating the hip joint. The special curved osteotome is inserted manually until it reaches the bottom of the groove, and the posterior cortex is cut. After the top of the teardrop is divided fluoroscopically, the anterior ischial cortex is osteotomized with a sharpened spiked Cobb elevator at the infracotyloid groove. An angled curved osteotome is used for the osteotomy of the superior area of the teardrop area. The bone fragment is rotated with a spreader and an angled retractor, and fixed with 2 absorbable screws. Beta-tricalcium phosphate blocks are inserted into the bone gap. The osteotomized wedge-shaped iliac bone is repositioned and fixed. Alternatives: Alternatives include the Bernese periacetabular osteotomy, rotational acetabular osteotomy, and triple innominate osteotomy. Rationale: Bernese periacetabular osteotomy utilizes an anterior approach, cuts into the QLS, and preserves the posterior column. In contrast, SPO preserves the QLS and does not cut the pubis. These features of SPO have some advantages. The large osteotomized surface is advantageous for osseous fusion, and preserving the QLS and pubis protects the trunk of the obturator artery. Furthermore, the preservation of the connection between the ilium, ischium, and pubis in SPO maintains a more stable pelvic ring than in Bernese periacetabular osteotomy. The osteotomy line is arranged to prevent leg shortening caused by thin medial bone stock of the bone fragment. Although splitting the teardrop area in SPO is somewhat technically difficult, particularly in cases with a thin teardrop, it can be safely done with use of preoperative 3-dimensional planning and appropriate surgical technique.In addition, the use of our medial wedge-shaped osteotomy at the iliac crest has 2 advantages: protection of the lateral femoral cutaneous nerve and preservation of the attachment of the tensor fascia latae muscle. Expected Outcomes: The advantages of SPO are a stable pelvic ring postoperatively, reduced risk of nonunion at the osteotomy site, no risk to the trunk of the obturator artery, preservation of the blood supply to the bone fragment, a small incision, and early muscle recovery. Important Tips: Preoperative 3-dimensional planning of the osteotomy design is essential.The special curved osteotomes are designed so that osteotomy of the posterior cortex is completed when the handles are perpendicular to the pelvis.The special curved osteotomes are made with a radius of either 50 or 60 mm, which are the most suitable sizes for the Japanese population. Larger-diameter osteotomes may be required for different races.As the rotated bone fragment is relatively small, it is difficult to obtain rigid fixation of the osteotomy site. Hence, the fragment can move slightly in the early phase after surgery. Careful rehabilitation is needed. Acronyms and Abbreviations: AIIS = anterior inferior iliac spineASIS = anterior superior iliac spineLFCN = lateral femoral cutaneous nerveG.T. = greater trochanterK-wire = Kirschner wireBeta (ß)-TCP = beta-tricalcium phosphate.

A Novel Minimally Invasive Spherical Periacetabular Osteotomy: Pelvic Ring Preservation and Patient-Specific Osteotomy by Preoperative 3-Dimensional Templating.

BACKGROUND: Spherical periacetabular osteotomy (SPO) is a novel osteotomy involving splitting the teardrop, using patient-specific preoperative planning, and requiring only a 7-cm skin incision. We report preoperative planning methods and short-term results of SPO. METHODS: In preoperative planning, computed tomography (CT) images were imported into 3-dimensional templating software. The radius of the curved chisel was mapped to pass through the teardrop, the infracotyloid groove of the ischium, and the area between the anterior superior iliac spine and the anterior inferior iliac spine. The osteotomy height and the predicted depth of osteotome insertion were measured, and those values were reproduced during surgery. We performed a retrospective analysis of data on 52 consecutive patients (55 hips) with hip dysplasia who underwent SPO and were followed for at least 2 years: 27 hips had Tönnis grade 0, 21 had grade 1, and 7 had grade 2. The mean age at surgery was 38 years (range, 17 to 56 years). The rotated bone fragment and iliac crest were fixed with absorbable screws. Statistical analysis was performed with the paired t test. RESULTS: The mean (range) of the lateral center-edge and sourcil angles were 6.0° (-20° to 18°) and 26.0 (13° to 38°), respectively, before surgery and 30.0° (15° to 43°) and 3.8° (-4° to 27°), respectively, after surgery (p < 0.001). However, 11 hips (20%) showed a loss of correction of bone rotation (<3 mm) or the sourcil angle (<3°). Radiographs showed bone union in all hips within 3 months after the surgery. Early second surgery related to absorbable screws was performed in 2 hips. No patient had required conversion to total hip arthroplasty at the time of writing. Clinical scores were significantly improved at the 2-year follow-up (p < 0.001). Paresthesia of the lateral femoral cutaneous nerve area was very common but had resolved in 92% of the patients at the 2-year follow-up. CONCLUSIONS: SPO is a novel minimally invasive periacetabular osteotomy that has the potential disadvantage of early loss of correction (observed in 20% of the hips in the present study) but may provide the benefit of decreasing the risk of nonunion at the pubis osteotomy site. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Bone ingrowth observed in a cup removed during revision surgery for early dislocation after primary THA: A case report.

INTRODUCTION AND IMPORTANCE: Recently cementless total hip arthroplasty (THA) has shown good long-term results with excellent stability resulted from the porous coating of the implant. A hydroxyapatite-tricalcium phosphate (HA-TCP) coating on the porous surface is expected to promote bone ingrowth and to improve initial fixation of the implant. Here we report a case of bone ingrowth observed in a cup removed during revision surgery for early dislocation, 37 days after primary THA using a porous coating cup with HA-TCP. CASE PRESENTATION: A 61-year-old woman who has bilateral osteoarthritis underwent same-day bilateral THA. Both sides used porous coating cups with HA-TCP. Line-to-line technique and screw fixation were utilized. Anterior dislocation of the left hip occurred on days 27 and 31, and we performed cup revision on day 37 after surgery. We noted bone-like tissue on the posterior surface of the cup and in a vacant screw hole. Bone tissue was also confirmed in pathological findings. CLINICAL DISCUSSION: Studies in animals have confirmed early bone ingrowth about 4 weeks after surgery with HA-TCP coated implants. In humans, the earliest report of bone ingrowth in cups is for a cup without HA-TCP coating, detected 5 weeks after surgery. In the present case, we used a porous coating cup with HA-TCP, and bone ingrowth was confirmed at approximately the same time as for the previous case. CONCLUSION: Early clinical bone ingrowth was confirmed in an HA-TCP coated cup, occurring at about the same time after surgery as in previous reports.

Long-Term Outcomes for Cementless Anatomic Femoral Components, Compared by Area of Porous Coating, in Patients Younger Than 50 Years Treated for Hip Dysplasia.

BACKGROUND: We investigated whether the proximal circumferential porous coating of cementless stems would make implant survival of >20 years possible in young patients. METHODS: Data for patients younger than 50 years with hip dysplasia who had an anatomic stem implanted with a proximal porous coating with hydroxyapatite/tricalcium phosphate were reviewed. Noncircumferential porous (non-C-type) stems were used in 17 hips (13 cases), and circumferential porous (C-type) stems were used in 87 hips (68 cases). Acetabular components with conventional polyethylene were used for all hips. The mean ages at surgery for patients with non-C-type stems and those with C-type stems were 43.3 and 44.7 years, respectively. Stems that had not loosened were retained at the time of acetabular revision. The average duration of follow-up for patients with non-C-type stems was 26.9 years and was 22.3 years for those with C-type stems. RESULTS: Mean survival rates as determined by the Kaplan-Meier method were 74.9% at 20 years and 59.9% at 25 years for non-C-type stems and were 100% at 20 years and 94.0% at 25 years for C-type stems. The survivorship for C-type stems was significantly higher than that for non-C-type stems (P < .01). Focal osteolysis in the shoulder of 37 hips with C-type stems suppressed the spread of osteolysis to the distal femur. CONCLUSION: Anatomic femoral stems with a circumferential porous coating provide excellent durability in patients with hip dysplasia who are 50 years of age or younger. LEVEL OF EVIDENCE: Therapeutic Level IV.

Satisfactory Outcomes in Patients Operated With Primary Total Hip Arthroplasty for Perthes-like Deformities: Results From a Surgical Technique Utilizing a Conical Stem, an Elevated Hip Center, and No Shortening Femoral Osteotomy.

BACKGROUND: Total hip arthroplasty (THA) performed on patients with Perthes-like deformities are technically challenging because of the patient's abnormal hip anatomy. Patients with Perthes-like deformities are at a higher risk of revision, aseptic loosening, nerve injury, and intraoperative fracture after THA, especially if shortening osteotomies are performed. This analysis sought to examine the clinical and radiographic outcomes of a patient cohort with Perthes-like deformities receiving THA with a conical stem, an elevated hip center, and no shortening femoral osteotomy. METHODS: Twenty-six patients (27 hips) received THA with MODULUS femoral stems, ceramic or metal femoral heads, and highly cross-linked polyethylene liners between April 2011 and March 2016. All patients were treated at a single center by 4 participating surgeons. Patients completed 2 questionnaires preoperatively and at the final follow-up visit (between 1 and 5 years postoperatively): Harris Hip Score and Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire. Differences in patient-reported outcome measures (PROM) scores were measured by paired t-tests. Preoperative and postoperative anteroposterior radiographs were analyzed to monitor patient outcomes. RESULTS: Significant clinical improvements were observed in all individual subcategories of the Harris Hip Score and of the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire; the largest magnitude improvements were observed in the subcategory of pain relief for both questionnaires. No complications, including intraoperative and postoperative femoral fractures, nerve palsy, dislocations, or deep venous thrombosis, were observed. CONCLUSION: This study found that patients treated with an elevated hip center and low stem-positioning technique using a conical, modular implant system had good clinical outcomes and did not suffer complications at the mean follow-up from surgery of 2.8 years (range: 1-5 years).

Bone formation at Ti-6Al-7Nb scaffolds consisting of 3D honeycomb frame and diamond-like carbon coating implanted into the femur of beagles.

We fabricated Ti-6Al-7Nb bone scaffolds with 5 mm diameter and 20 mm length comprise of a three-dimensional (3D) honeycomb frame structure of truncated octahedra created by selective laser sintering 3D printing. The honeycomb frame was then coated with 0.1 µm thick diamond-like carbon (DLC) to increase biocompatibility. A round rod of Ti-6Al-7Nb alloy (ASTM F1295) was as a control material. They were implanted into the femur bones of beagles to evaluate bone morphometrics and to investigate changes in the transcriptome of the new bone tissue using DNA microarray analysis and real-time polymerase chain reaction (PCR). In the present report, the 3D honeycomb material with and without DLC film consisting of a-C:H is referred to as 3D_a-C:H and 3D_non, respectively. At 3 weeks after implantation, the 3D_non had more contact between the new and artificial bones compared with the control, and the 3D_a-C:H had more contact between the new and artificial bones compared with the control and 3D_non. Furthermore, 3D_a-C:H showed even more new bone compared with the control and 3D_non. At 8 weeks after implantation, more appeared lamellar bone with the 3D_a-C:H implant than those with the control and 3D_non. The real-time PCR results at 1 week of implantation revealed higher expression levels of VEGF, RANKL, and NOTCH2 expression with 3D_a-C:H than with 3D_non and control. As a result of real-time PCR at 2 weeks of implantation, OPN and CTSK expressions were found to be higher with 3D_a-C:H and 3D_non than that with the control.

Catastrophic failure of cup revision hip arthroplasty due to undiagnosed Paget disease of bone: A case report.

INTRODUCTION: Paget's disease of bone (PDB) is a localized chronic osteopathy, apparently not genetic in origin, and frequently diagnosed from incidental radiographic images. The disease is characterized by deformation, hypervascularity, and structural weakness of the bone and by changes in joint biomechanics. Most cases of PDB can be easily diagnosed from radiographic findings, but monostotic cases may be problematic and require invasive procedures. PRESENTATION OF CASE: A 70-year-old woman had re-revision surgery for early catastrophic failure of an isolated cup revision hip arthroplasty because of undiagnosed PDB 21 years after the primary total hip arthroplasty. To identify the pathomechanism of early failure, we performed bone biopsy on the right iliac crest. Histopathological findings showed a mosaic pattern in the bone characteristic of PDB. Prior to the planned re-revision surgery, we treated the PDB with denosumab until the patient's serum level of alkaline phosphatase (ALP) was within the normal limits. Two months after denosumab treatment, we performed re-revision hip arthroplasty using a structural allograft and a Kerboull-type reinforcement device. DISCUSSION: The delay in correct diagnosis of PDB was associated with the rapid destruction of pelvic bone. The preoperative use of antipagetic medication could decrease the risk of implant loosening and may be warranted to mitigate that risk. CONCLUSION: In patients with a failed arthroplasty, thoughtful evaluation is warranted for preoperative antipagetic medication in order to reduce PDB activity and potentially decrease the risk of implant loosening. This paper offers some steps for such risk reduction in the workup before revision surgery.

Dual mobility acetabular construct with freedom constrained liner for treatment of recurrent dislocations after total hip arthroplasty: A case report and literature review.

INTRODUCTION: Recurrent dislocation after total hip arthroplasty (THA) using the dual mobility cup system can present challenges, while dual-mobility THA bearings can improve stability in both primary and revision total hip arthroplasties. PRESENTATION OF CASE: A 72-year-old woman with a history of schizophrenia underwent a left primary THA using the G7 dual mobility system. Two postoperative posterior dislocations occurred within 2 months post-surgery. The patient underwent revision surgery in which the metal liner and dual mobility head were exchanged using the Freedom constrained liner system without revision of the cup and stem. As of this writing, 28 months after the revision surgery, no further dislocations have occurred. The implants are stable, and the patient has good range of motion. DISCUSSION: Dual-mobility bearings are utilized to improve stability in both primary and revision total hip arthroplasties, but even if the dual mobility system is chosen, it sometimes fails to prevent postoperative dislocation. Although a relatively high failure rate has been reported in THA using the constrained liner system, this patient's clinical course suggests that the G7 Freedom constrained liner system can be an efficacious option for some patients with unstable hip joints who undergo THA using the dual mobility system. CONCLUSION: A modern constrained liner system such as the G7 Freedom liner may provide an improved salvage solution for joint instability in dual mobility THA.

External iliac vein compression and lower-extremity swelling caused by an iliopectineal ganglion: a case report.

BACKGROUND: A hip joint ganglion is a rare cause of lower-extremity swelling. CASE PRESENTATION: We report a case of a Japanese patient with ganglion of the hip with compression of the external iliac/femoral vein that produced signs and symptoms mimicking those of deep vein thrombosis. CONCLUSIONS: Needle aspiration of the ganglion was performed, and swelling of the lower extremity promptly decreased. At 7.5 years after aspiration, there was no recurrence of swelling of the leg. Although the recurrence rate for ganglions after needle aspiration is high, it is worthwhile trying aspiration first.