The influence of COVID-19 epidemic on the number of orthopaedic surgeries in Japan.

BACKGROUND: There is limited data on the impact of COVID-19 epidemic on the number of orthopaedic surgeries in Japan. METHODS: We conducted a nationwide hospital survey asking for the monthly number of orthopaedic surgeries performed at each facility from January 2019 to June 2021. Those facilities that had performed at least 100 surgeries in 2019 were included for analyses. The facilities were further grouped by prefecture and by hospital characteristics. A brief health economic evaluation was also performed. Risk ratios were compared using univariate analyses with P < 0.05 considered statistically significant. RESULTS: Questionnaire was sent to 1988 hospitals with 1671 hospitals (84%) responding. The survey data indicated a total number of orthopaedic surgeries decreased in 2020 compared to 2019 (1,061,541 vs 1,119,955 P < 0.01), and also for the first six months of 2021 compared to the same period in 2019 (530,388 vs 550,378 P < 0.01). In 2020, over 50% of all facilities in nearly all of the prefectures saw a decline in surgical procedures. The risk of incurring more than a 25% decease in the number of surgeries was significantly higher in 2020 for class I designated medical institutions compared to those that were not designated for any types of infectious diseases among the institutions with a tertiary emergency medical center in 2020 (crude risk ratio 2.9: 95% CI 1.2-7.4, p = 0.02) and in 2021 (crude risk ratio 4.7: 95% CI 1 0.9-12.1, p < 0.01). The estimated total nationwide decrease of revenue were in the range of approximately ¥29.2 to ¥116.8 billion per year for orthopaedic surgeries alone. CONCLUSION: There was a statistically significant decrease in the number of orthopaedic surgeries in Japan. The magnitude of the decline varied by prefectures and hospital characteristics, with the greater impact imposed on medical institutions with higher classification functions. The estimated immediate health economic impact was sizable.

Iodine-supported implants in prevention and treatment of surgical site infections for compromised hosts: a prospective study.

BACKGROUND: Surgical site infection (SSI) is a common complication following orthopedic implantation. We developed an iodine coating for titanium implants to reduce implant-related infections and conducted a prospective clinical study to evaluate the efficacy and potential drawbacks of iodine-supported implants. PATIENTS AND METHODS: Between July 2008 and July 2017, 653 patients (377 male and 27 female patients; mean age, 48.6) with postoperative infection or a compromised status were treated using iodine-loaded titanium implants. The mean follow-up period was 41.7 months. In 477 patients, iodine-supported implants were used to prevent infection and in 176 patients, to treat active infection (one-stage surgery, 89 patients; two-stage surgery, 87 patients). In the limbs and pelvis, the primary diagnoses included the following: 161 tumors, 92 deformities/shortening, 47 pseudarthrosis, 42 fractures, 32 infected TKA, 25 osteoarthritis, 21 pyogenic arthritis, 20 infected THA, and 6 osteomyelitis. In the spinal cases, there were 136 cases of tumors, 36 cases of pyogenic spondylitis, and 35 cases of degeneration. Five modes of implant failure were identified and classified as follows: soft tissue failure (type 1), aseptic loosening (type 2), structural failure (type 3), infection (type 4), and tumor progression (type 5). RESULTS: The overall failure rate in our series was 26.3% (172/653). There were 101 mechanical failures, including 22 type 1, 20 type 2, and 59 type 3 failures. Non-mechanical causes accounted for 71 failures, including 45 type 4 and 26 type 5 failures. The overall incidence of infections was 6.8%. The mean time to the onset of infection after implantation was 9.1 months. The overall infection rate was 3.7% in the prevention cases and 15.3% in the treatment cases. There was no difference between one-stage replacement (14.6%) and two-stage replacement (16.0%). There were 11 cases of treatment for SSI of spine surgery, and the re-infection rate was 0% using iodine-coated instruments. CONCLUSIONS: The five modes of failure of the iodine-supported implant were satisfactory compared with previous reports. In particular, because the infection rate of iodine-coated implants used for compromised hosts is low compared with other methods, postoperative infection is more easily controlled. It can be considered highly effective for spinal infections that require one-stage revision surgery. LEVEL OF EVIDENCE IV: Trial registration Prospective, Observation study.

Combined adipose-derived mesenchymal stem cell and antibiotic therapy can effectively treat periprosthetic joint infection in rats.

Periprosthetic joint infection (PJI) is characterized by biofilm infection, which is difficult to alleviate while preserving implant integrity. Furthermore, long-term antibiotic therapy may increase the prevalence of drug-resistant bacterial strains, necessitating a non-antibacterial approach. Adipose-derived stem cells (ADSCs) exert antibacterial effects; however, their efficacy in PJI remains unclear. This study investigates the efficacy of combined intravenous ADSCs and antibiotic therapy in comparison to antibiotic monotherapy in a methicillin-sensitive Staphylococcus aureus (MSSA)-infected PJI rat model. The rats were randomly assigned and equally divided into 3 groups: no-treatment group, antibiotic group, ADSCs with antibiotic group. The ADSCs with antibiotic group exhibited the fastest recovery from weight loss, with lower bacterial counts (p = 0.013 vs. no-treatment group; p = 0.024 vs. antibiotic group) and less bone density loss around the implants (p = 0.015 vs. no-treatment group; p = 0.025 vs. antibiotic group). The modified Rissing score was used to evaluate localized infection on postoperative day 14 and was the lowest in the ADSCs with antibiotic group; however, no significant difference was observed between the antibiotic group and ADSCs with antibiotic group (p < 0.001 vs. no-treatment group; p = 0.359 vs. antibiotic group). Histological analysis revealed a clear, thin, and continuous bony envelope, a homogeneous bone marrow, and a defined, normal interface in the ADSCs with antibiotic group. Moreover, the expression of cathelicidin expression was significantly higher (p = 0.002 vs. no-treatment group; p = 0.049 vs. antibiotic group), whereas that of tumor necrosis factor (TNF)-α and interleukin(IL)-6 was lower in the ADSCs with antibiotic group than in the no-treatment group (TNF-α, p = 0.010 vs. no-treatment group; IL-6, p = 0.010 vs. no-treatment group). Thus, the combined intravenous ADSCs and antibiotic therapy induced a stronger antibacterial effect than antibiotic monotherapy in a MSSA-infected PJI rat model. This strong antibacterial effect may be related to the increased cathelicidin expression and decreased inflammatory cytokine expression at the site of infection.

Risk factor analysis on perioperative greater trochanteric fracture of total hip arthroplasty via anterolateral approach.

INTRODUCTION: A greater trochanteric fracture is a perioperative complication of primary total hip arthroplasty (THA) via an anterolateral approach. Although surgeons determine risk factors in the preoperative planning phase, no study explored the relationship between the planned femoral implant and greater trochanter. This study attempts to determine the risk factors for perioperative greater trochanteric fractures in primary THA via an anterolateral approach. MATERIALS AND METHODS: This retrospective single-institution study enrolled 440 patients (66 males and 374 females) who underwent primary THA via an anterolateral approach with a minimum follow-up of six months. First, we selected patients with perioperative greater trochanteric fractures, regardless of the need for additional surgery. Second, we investigated the risk factors for perioperative greater trochanteric fractures using the patients' demographic data, operative data, and femoral geometry data via univariate and multivariate analyses. RESULTS: Perioperative greater trochanteric fractures occurred in 30 joints (30/440, 6.8%), and all cases were reported in women. Multivariate analysis revealed that in cases where the top of the great trochanter was inside the longitudinal central axis of the planned femoral stem in three-dimensional templating (Type B) was the only independent risk factor for perioperative greater trochanteric fracture (odds ratio, 14.6; 95% confidence interval, 5.88-36.1; P < 0.001). CONCLUSION: This study identified female sex and Type B femoral geometry as risk factors for perioperative greater trochanteric fracture via an anterolateral approach. Our results may reduce the incidence of perioperative greater trochanteric fractures associated with primary THA.

Risk factors that hinder locomotive syndrome improvement following surgery for musculoskeletal diseases in older patients: A multicentre prospective study.

OBJECTIVES: This study aimed to evaluate preoperative and post-operative locomotive syndrome (LS) in older adults undergoing surgical treatment for musculoskeletal diseases of the lumbar spine and lower extremities and identify risk factors that impede LS improvement after surgery. METHODS: The baseline evaluation included 471 patients 65 years or older [276 in the pre-old-age (65-74 years) group; 195 in the old-age (75 years or older) group] and examined the preoperative and post-operative LS data. The second evaluation performed to identify risk factors, including anthropometric measurements, comorbidity, and frailty, that hinder LS improvement after surgery included 378 patients with preoperative LS Stage 3. RESULTS: Preoperatively, 80% of the patients had LS Stage 3; this rate decreased to 40% post-operatively. Half of the patients exhibited post-operative LS improvement. The LS improvement rate was higher in the pre-old-age group than in the old-age group. According to the multiple logistic regression analysis, old age, high body mass index, weak hand grip strength, and high 5-factor modified frailty index score were significant risk factors that hinder LS improvement after surgery. CONCLUSIONS: Ageing, obesity, weak muscle strength, and frailty can hinder LS improvement in older patients who undergo surgery.

Large intraosseous chronic expanding hematoma after total hip arthroplasty presenting with chronic disseminated intravascular coagulation: a case report and literature review.

BACKGROUND: A chronic expanding hematoma (CEH) is a rare complication caused by surgery or trauma; it mostly affects the soft tissues, such as those in the trunk or extremities. We present the first case of a large intraosseous CEH presenting with chronic disseminated intravascular coagulation (DIC), 22 years after total hip arthroplasty (THA); the CEH was treated with a single-stage excision and revision THA. CASE PRESENTATION: A 67-year-old man presented to our hospital with left thigh pain and an enlarging mass. He had no history of trauma, anticoagulant use, or a collagen vascular disorder. The patient initially declined surgery. Two years later, radiographs and computed tomography images revealed progressive osteolysis, marginal sclerosis, and calcification in the left femur, in addition to loosening of the femoral component. Laboratory data revealed anemia and chronic DIC of unknown causes. Magnetic resonance imaging revealed a "mosaic sign" on the mass, indicating a mix of low- and high-signal intensities on T2-weighted images. Needle biopsy prior to surgery revealed no infection or malignant findings. An intraosseous CEH was suspected due to extensive osteolysis and loosening of the femoral component. No other factors that could induce chronic DIC were identified, such as sepsis, leukemia, cancer, trauma, liver disease, aneurysms, or hemangiomas. Therefore, we speculated that the anemia and chronic DIC were caused by the large intraosseous CEH. A single-stage revision THA with surgical excision was performed to preserve the hip function and improve the chronic DIC. The postoperative histopathological findings were consistent with an intraosseous CEH. The anemia and chronic DIC improved after 7 days. There was no recurrence of intraosseous CEH or chronic DIC at the 6-month follow-up. The left thigh pain improved, and the patient could ambulate with the assistance of a walking frame. CONCLUSIONS: The loosening of the femoral component caused persistent movement, which may have caused intraosseous CEH growth, anemia, and chronic DIC. It is important to differentiate CEHs from malignant tumors with hematomas. Furthermore, the "mosaic sign" noted in this case has also been observed on magnetic resonance images in other cases of CEH.

Importance of Three-Dimensional Evaluation of Surgical Transepicondylar Axis in Total Knee Arthroplasty.

In total knee arthroplasty, the surgical transepicondylar axis (SEA) is one of the most reliable rotation axes for stabilizing of the patellofemoral joint. The SEA is identified with reference to the lateral epicondyle and the medial sulcus of the medial epicondyle. However, these two structures rarely appear on the same plane on computed tomography (CT), and it is necessary to take two points in separate images. Many surgeons measure the SEA on the same image (pseudo SEA) instead. We aimed to determine the difference between true SEAs and pseudo SEAs. A total of 31 normal knees and 24 varus knees were included in this study. Three-dimensional (3D) models of the femur were reconstructed from CT images, and a reconstructed plane was made using the International Society of Biomechanics coordinate system. Pseudo SEAs drawn in the plane passing through the lateral epicondyle and medial sulcus were defined as l-SEA and m-SEA, respectively. L-SEA, m-SEA, true SEA, and posterior condylar axis (PCA) were projected onto the International Society of Biomechanics coordinate plane and, "p l-SEA," "p m-SEA," "p true SEA," and "p PCA" were obtained. The true SEA angle was defined as the angle between p true SEA and p PCA. The l-SEA angle or m-SEA angle was defined as the angle between the p l-SEA or p m-SEA and p PCA, respectively. There were no statistically significant differences between true SEA angle (2.64 ± 2.01 degrees) and pseudo SEA angle (l-SEA angle: 2.74 ± 2.07 degrees, m-SEA: 2.54 ± 2.19 degrees). Conversely, 12 knees in the normal group and 2 knees in the varus group had differences of more than 1 degree (p = 0.01). Among them, 6 knees in the normal group and 0 knees in the varus group had a difference of 2 degrees or more (p = 0.03). In most cases, pseudo SEA can be substituted for true SEA.

Does intraoperative periprosthetic occult fracture of the acetabulum affect clinical outcomes after primary total hip arthroplasty?

INTRODUCTION: The frequency of intraoperative periprosthetic occult fracture of the acetabulum (IPOA) in primary total hip arthroplasty (THA) is relatively high. However, the effect of this fracture on clinical outcome and survival of primary THA remains unknown. This study aimed to determine the impact of IPOA on the outcomes of primary THA during a minimum follow-up of 5 years. MATERIALS AND METHODS: This retrospective case-control study compared the outcomes of primary THA with or without IPOA during a minimum 5-year follow-up. Thirty-eight patients who underwent primary THA with IPOA (O group) were matched to 76 patients without IPOA (C group) between 2004 and 2013 based on age, sex, body mass index, primary diseases, cup diameter, cup design, and additional dome screw. Both groups underwent the same rehabilitation programs after surgery. We evaluated the Japanese Orthopaedic Association clinical outcomes score; postoperative complications, such as nerve injury, dislocation, heterotopic ossification, iliopsoas impingement, or infection; and radiographic outcomes. Additionally, we performed Kaplan-Meier survival analysis with cup aseptic loosening, cup failure revision, and all-cause revision as the endpoints. RESULTS: There were no significant differences in the pre- and postoperative clinical scores, postoperative complication rates, and cup sagittal rotation between the two groups. Radiographic evaluations showed no aggravation of cases to overt fractures. Bone ingrowth was observed in all cases, and none of the acetabular cups had a progressive radiolucent line ≥ 2 mm in all the 3 acetabular zones. Ten-year survival rates for cup aseptic loosening and cup failure revision were 100% in both groups; those for all-cause revision were 97.4% (92.0-100%) and 100% in the O and C groups, respectively (p = 0.157). CONCLUSIONS: Primary THA with IPOA provides favorable mid- to long-term outcomes. On IPOA diagnosis, although radiographic follow-up is necessary, additional treatments or rehabilitation programs are not required. Furthermore, postoperative computed tomography images for the detection of IPOA may be unnecessary.

Evaluation of locomotive syndrome in patients receiving surgical treatment for degenerative musculoskeletal diseases: A multicentre prospective study using the new criteria.

OBJECTIVES: This study aimed to evaluate the condition of patients with locomotive syndrome (LS) and their improvement after undergoing surgery for degenerative musculoskeletal diseases using the new criteria, including stage 3. METHODS: In total, 435 patients aged ≥40 years (167 middle-aged and 268 older) were divided into four groups based on the disease location: the lumbar (n = 118), hip (n = 191), knee (n = 80), and foot and ankle (n = 46) groups. Patients were evaluated by pre- and 1 year postoperative LS risk tests, including the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale. RESULTS: The pre- and postoperative prevalence of LS stage 3 were 78% and 29%, respectively. The postoperative LS stage improved in 62% of patients (77% and 53% in the middle-aged and older groups, respectively). Overall, the knee group showed the worst results, and the foot and ankle groups showed the best pre- and postoperative results. The pre- and postoperative prevalence of LS stage 3 according to the 25-Question Geriatric Locomotive Function Scale were comparable to those based on the total assessment. CONCLUSIONS: The new LS stage criteria are appropriate, and the 25-Question Geriatric Locomotive Function Scale is a good option for evaluating patients requiring surgery.

The influence of pelvic tilt on stress distribution in the acetabulum: finite element analysis.

BACKGROUND: Finite element analysis (FEA) has been previously applied for the biomechanical analysis of acetabular dysplasia and osteotomy. However, until now, there have been little reports on the use of FEA to evaluate the effects of pelvic tilt on stress distribution in the acetabulum. METHODS: We used the Mechanical Finder Ver. 7.0 (RCCM, Inc., Japan) to construct finite element models based on 3D-CT data of patients, and designed dysplasia, borderline, and normal pelvic models. For analysis, body weight was placed on the sacrum and the load of the flexor muscles of the hip joint was placed on the ilium. The pelvic tilt was based on the anterior pelvic plane, and the pelvic tilt angles were -20°, 0°, and 20°. The load of the flexor muscle of the hip joint was calculated using the moment arm equation. RESULTS: All three models showed the highest values of von Mises stress in the -20° pelvic tilt angle, and the lowest in the 20° angle. Stress distribution concentrated in the load-bearing area. The maximum values of von Mises stress in the borderline at pelvic tilt angles of -20° was 3.5Mpa, and in the dysplasia at pelvic tilt angles of 0° was 3.1Mpa. CONCLUSIONS: The pelvic tilt angle of -20° of the borderline model showed equal maximum values of von Mises stress than the dysplasia model of pelvic tilt angle of 0°, indicating that pelvic retroversion of -20° in borderline is a risk factor for osteoarthritis of the hip joints, similar to dysplasia.

Contralateral Lower-Limb Functional Status Before Total Hip Arthroplasty: An Important Indicator for Postoperative Gait Speed.

BACKGROUND: Postoperative gait speed, especially comfortable gait speed, is an important factor for predicting function after total hip arthroplasty (THA). In this study, we examined factors related to gait speed, including preoperative lower and upper-limb functional parameters and postoperative lower-limb alignment. In addition, we examined factors related to postoperative good comfortable gait speed (≥1.34 m/s: one indicator of a good clinical outcome). The purpose of this study was to determine if better preoperative functional parameters had a positive effect on postoperative gait speed. METHODS: This prospective case-control study included 91 patients with hip osteoarthritis who underwent unilateral THA. Patients who had undergone a prior hip surgical procedure or had Crowe type-3 and 4 hips, complications after THA, knee osteoarthritis-related pain, and severe lumbar conditions were excluded. The 1-leg standing time (OLST) and knee extensor strength of the operatively treated side and the contralateral side and the functional reach test were examined preoperatively and at 1 year postoperatively. The leg-length discrepancy and global offset compared with the contralateral side and leg lengthening were examined using 3-dimensional models captured through computed tomographic scans. RESULTS: The preoperative contralateral side OLST was a significant factor (p < 0.001) for postoperative comfortable gait speed, and the preoperative contralateral-side knee extensor strength was a significant factor (p = 0.018) for postoperative maximum gait speed. Leg-length discrepancy and differences in global offset after THA were not significant factors for postoperative gait speed. The preoperative comfortable gait speed with a cutoff value of 1.115 m/s (area under the receiver operating characteristic curve, 0.690 [95% confidence interval, 0.569 to 0.810]; p = 0.003; sensitivity of 65.5% and specificity of 74.2%) was an independent factor associated with a good postoperative comfortable gait speed. Preoperative contralateral-side OLST was a significant factor (p = 0.027) for preoperative comfortable gait speed. CONCLUSIONS: The preoperative contralateral-side, lower-limb functional status is a significant factor for postoperative gait speed. Early surgical intervention before the contralateral-side function declines or a preoperative rehabilitation intervention on the contralateral side may improve THA outcome. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Association of low back pain with muscle weakness, decreased mobility function, and malnutrition in older women: A cross-sectional study.

BACKGROUND: Low back pain (LBP) and decreased mobility function are common problem among older people. Muscle weakness has been reported as a risk factor for these conditions, and exercise therapy can improve them. We created a novel exercise device that also measures abdominal trunk muscle strength. Malnutrition has also emerged as a major problem among older people. Muscle is a direct key linking decreased mobility function and malnutrition. This study aimed to examine the associations of LBP with not only decreased physical function and muscle weakness but also nutritional status of older people. METHODS: We examined the associations of LBP with muscle weakness, decreased mobility function (locomotive syndrome [LS]), and malnutrition among older women. The study included 101 female patients aged 60 years or older scheduled to undergo surgery for degenerative lower extremity diseases. Preoperatively, physical tests including abdominal trunk muscle strength assessment using the device and laboratory tests were conducted. Subjects with LBP (numerical rating scale ≥2; range, 0-4) during the preceding month were allocated to the LBP group (n = 36). Other subjects were allocated to the non-LBP group (n = 65). RESULTS: The LBP group had lower abdominal trunk and knee extensor muscle strength, lower serum albumin, and hemoglobin levels as blood biomarkers associated with malnutrition risk, and higher LS test scores than the non-LBP group. A multivariate analysis showed that abdominal trunk muscle weakness and advanced LS were associated with LBP. LBP intensity was negatively correlated with abdominal trunk and knee extensor muscle strength and positively correlated with the LS test score. The serum hemoglobin level was negatively correlated with the LS test score. CONCLUSION: Abdominal trunk muscle weakness and decreased mobility function were associated with LBP among older women.

Comparison of mid-term clinical results between cementless and cemented femoral stems in total hip arthroplasty with femoral shortening osteotomy for Crowe type IV hips.

INTRODUCTION: This report is the first study to compare the clinical outcomes between cementless and cemented femoral prostheses in total hip arthroplasty (THA) with subtrochanteric femoral shortening osteotomy for Crowe type IV hips. MATERIALS AND METHODS: We identified 26 hips in 20 patients who had undergone cemented (n = 13) or cementless (n = 13) THA with subtrochanteric femoral shortening osteotomy for Crowe type IV hips with a minimum follow-up period of 2 years. The mean follow-up period was 60.8 ± 33.9 months (24-120 months). We compared radiological findings, postoperative clinical recoveries, postoperative complications, and implant survival rates. RESULTS: In both groups, there were no cases of aseptic loosening for the acetabular and femoral implant. In terms of bone union at the osteotomy site, the mean duration was significantly longer in the cemented group (9.8 ± 4.2 months) than in the cementless group (5.0 ± 1.9 months). The clinical hip score in gait and pain at 3 months postoperatively was significantly higher in the cemented group than in the cementless group, while there were no significant changes at other timepoints between two groups. The number of postoperative complications was not significantly different between the two groups. The implant survival rate was 92% in the cementless group and 100% in the cemented group at 5 years postoperatively (P = 0.31). CONCLUSIONS: The cemented femoral prosthesis is superior to the cementless femoral prosthesis for early clinical recovery, while the duration required to achieve bone union at the osteotomy site is longer in the cemented femoral prostheses. It is possible for surgeons to perform successful hip reconstructions, regardless of the fixation method used for THA with shortening femoral osteotomy.

Improvement of locomotive syndrome with surgical treatment in patients with degenerative diseases in the lumbar spine and lower extremities: a prospective cohort study.

BACKGROUND: The epidemiology, risk factors, and prevention of locomotive syndrome (LS) have been reported. However, the number of clinical studies about the efficacy of LS treatment, including surgery, has been limited. This study aimed to evaluate LS and its improvement in patients undergoing surgeries for degenerative disease of the lumbar spine and lower extremities, and to discuss the effects of surgery on LS and the issues of LS assessment in these patients. METHODS: We enrolled 257 patients aged ≥60 years that underwent surgery for degenerative diseases of the lumbar spine and lower extremities and agreed to participate in the preoperative and 6- and 12-month postoperative LS examinations. According to the disease location, patients were divided into the lumbar (n = 81), hip (n = 106), knee (n = 43), and foot and ankle (n = 27) groups. Patients underwent LS risk tests, including the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale (GLFS-25) assessment. RESULTS: The preoperative prevalence of LS stage 2 was 95%. Only the hip group showed significant improvements in the stand-up test. The knee group showed the worst results in the stand-up and two-step tests at all time points. All four groups had significant improvements in GLFS-25 scores. Approximately 40% of all patients had improvement in their LS stage postoperatively. However, > 90% of the patients in the knee group had LS stage 2 postoperatively. CONCLUSION: Nearly all elderly patients requiring surgeries for degenerative diseases of the lumbar spine and lower extremities had advanced conditions (LS stage 2). Surgeries could be beneficial in alleviating LS. The LS stage 3 criteria should be established, and the use of the GLFS-25 assessment can be appropriate for advanced LS patients with severe musculoskeletal diseases requiring surgeries.

Combinational therapy with antibiotics and antibiotic-loaded adipose-derived stem cells reduce abscess formation in implant-related infection in rats.

Implant-related infection is difficult to treat without extended antibiotic courses. However, the long-term use of antibiotics has led to the development of multidrug- and methicillin-resistant Staphylococcus aureus. Thus, alternatives to conventional antibiotic therapy are needed. Recently, mesenchymal stem cells have been shown to have antimicrobial properties. This study aimed to evaluate the antimicrobial activity and therapeutic effect of local treatment with antibiotic-loaded adipose-derived stem cells (ADSCs) plus an antibiotic in a rat implant-associated infection model. Liquid chromatography/tandem mass spectrometry revealed that ADSCs cultured in the presence of ciprofloxacin for 24 h showed time-dependent antibiotic loading. Next, we studied the therapeutic effects of ADSCs and ciprofloxacin alone or in combination in an implant-related infection rat model. The therapeutic effects of ADSCs plus antibiotics, antibiotics, and ADSCs were compared with no treatment as a control. Rats treated with ADSCs plus ciprofloxacin had the lowest modified osteomyelitis scores, abscess formation, and bacterial burden on the implant among all groups (P < 0.05). Thus, local treatment with ADSCs plus an antibiotic has an antimicrobial effect in implant-related infection and decrease abscess formation. Thus, our findings indicate that local administration of ADSCs with antibiotics represents a novel treatment strategy for implant-associated osteomyelitis.

Patient-reported outcomes following primary total hip arthroplasty in Crowe type III or IV developmental dysplasia are comparable to those in Crowe type I: a case-control study of 96 hips with intermediate-term follow-up.

BACKGROUND: A few previous studies have investigated patient satisfaction after total hip arthroplasty (THA) according to the degree of pelvic deformity. This study compared patient-reported outcomes after primary THA for Crowe types III, IV and I dysplasia. METHODS: This retrospective, single-center, single-surgeon case-control study included patients who underwent primary THA between 2008 and 2016. We sent postal questionnaires to 38 patients with Crowe type III and IV dysplasia. Among the questionnaire respondents, 23 patients, excluding those with a follow-up period of < 1 year, were enrolled as the H group. The control group included 46 patients with Crowe type I, matched for sex, age, body mass index and surgical approach. To investigate the influence of femoral shortening osteotomy, the H group was divided according to whether femoral shortening osteotomy was performed. Ten patients underwent THA with femoral shortening osteotomy (FO group), while 12 patients underwent THA without femoral shortening osteotomy (N-FO group). Patient demographics, mean follow-up period, surgical information, pre- and postoperative leg length discrepancy (LLD), and perioperative complications were investigated. Clinical evaluations were performed using the Japanese Orthopaedic Association (JOA) scores, 36-item short-form survey (SF-36), net promotor score (NPS), visual analogue scale (VAS), and questionnaires. The VAS and SF-36 scores were determined only at final follow-up. RESULTS: The H and control groups were not significantly different in the postoperative JOA scores and SF-36. In the H group, VAS at the final follow-up was significantly higher, and significantly more patients felt that postoperative rehabilitation was serious, expressing that they underwent THA for LLD correction. In addition, the VAS scores in the FO group was higher than those in the N-FO group. Postoperative LLD was significantly greater in the H group than in the control group. Each group had an NPS of > 50. CONCLUSION: The postoperative VAS score was higher in Crowe type III and IV dysplasia than in Crowe type I dysplasia, but no significant differences were detected in the postoperative satisfaction, JOA score, and SF-36 score. These findings may help explain the effects of THA preoperatively to patients with Crowe type III and IV dysplasia. LEVEL OF EVIDENCE: Therapeutic Level 3b.

The use of density mapping in the analysis of thigh pain after total hip arthroplasty in patients with well-fixed tapered wedge stems.

PURPOSE: The mechanisms underlying thigh pain in patients with well-fixed cementless femoral components after total hip arthroplasty (THA) remains unclear. We hypothesized that the thigh pain is correlated with the initial contact state of the stem and aimed to investigate the relation between thigh pain and the initial contact state. MATERIALS AND METHODS: A total of 209 hips of 184 patients were analysed in this retrospective case-control study. The patients were divided into a thigh pain group (n = 13 hips) and a control group (without thigh pain, n = 196). Post-operative stem contact images were three-dimensionally visualized by a density mapping function using computed tomography data, which quantified the stem contact area according to Gruen zones. Thigh pain was defined as anterior or anterolateral pain upon loading at 3-month post-operatively. RESULTS: Thirteen hips (6.2%) had thigh pain; however, all the hips demonstrated stable bony ingrowth radiographically. The thigh pain group had a significantly lower contact area in zone 2 (p = 0.014). The multivariate logistic regression analysis showed that the contact area of zone 2 was negatively correlated with thigh pain [odds ratio (OR): 0.858, p = 0.018], and the canal flare index was negatively correlated with the development of thigh pain (OR: 0.336, p = 0.026). CONCLUSIONS: We identified an association between the initial contact state and post-operative thigh pain. Our data demonstrated that proper lateral contact prevents the occurrence of thigh pain in THA using a tapered wedge stem.

Association between total hip arthroplasty following periacetabular osteotomy and acetabular component overhang.

BACKGROUND: There is limited understanding of anterior acetabular component overhang, which induces groin pain, in post-periacetabular osteotomy (PAO) hips during conversion to total hip arthroplasty (THA). The aim of the study were to determine the following: (1) the differences in the amount of acetabular component overhang among pre-PAO hips and post-PAO hips in simulating THA; (2) the factors associated with the amount of component overhang in THA following PAO; (3) whether high component placement with elevation of the hip center by 10 mm reduces the amount of component overhang compared to the anatomical component position in THA following PAO. METHODS: Computer-based simulations of acetabular component implantation were performed using preoperative and postoperative CT data from 30 patients undergoing PAO. Implantation was performed thrice in each patient: in pre-PAO hips (anatomical component position) and post-PAO hips (anatomical and high component position). Component overhang was measured on the axial plane, which passes through the component center. RESULTS: Overhang was greater in post-PAO hips [mean (SD) overhang: 5.2 (2.9) mm, pre-PAO hips: 10.2 (4.6) mm, post-PAO hips-mean difference, 5.0 mm; p < 0.001]. A smaller distance between the pubic osteotomy and the acetabulum, and greater overhang in pre-PAO hips was independent factors associated with increased overhang in post-PAO hips. Overhang was smaller with the high component position than with the anatomical component position in post-PAO hips [mean (SD) overhang-3.5 mm (2.9) with high component position among post-PAO hips; mean difference, 6.6 mm; p < 0.001). Ten post-PAO hips with the anatomical component position had overhang of at least 12 mm (the likely threshold for groin pain). Of these, 9 hips had reduced overhang (< 12 mm) with the high component position. CONCLUSIONS: Acetabular component overhang was more severe in THA following PAO than in THA without prior PAO. Pubic osteotomy should be performed closer to the acetabular rim to prevent severe overhang in potential THA conversion cases. A high component position decreased the risk of severe overhang.

Postsurgical infection from using a computed tomography-based hip navigation system during total hip arthroplasty.

PURPOSE: A computed tomography (CT)-based hip navigation system is a useful tool for achieving precise implant alignment angle. However, it has the disadvantage of prolonged procedure duration. A prolonged procedure duration may increase the incidence of postoperative surgical site infection (SSI) or periprosthetic joint infection (PJI) following primary THA. Studies identifying whether CT-based hip navigation system increases the incidence of SSI and PJI compared to the free-hand technique for total hip arthroplasty (THA) are rare. The study aimed to assess whether the CT-based hip navigation system can cause SSI and PJI compared to the free-hand technique. METHODS: We investigated 366 patients with osteoarthritis who completed the minimum 2-year follow-up and underwent primary THAs (n = 435), including 70 hips in 62 patients of the non-navigation group and 365 hips in 304 patients of the navigation group. We compared the incidence rate of SSI and PJI between the non-navigation group and navigation group. RESULTS: Only three patients in the navigation group (0.8%) developed SSI or PJI, while no patient developed SSI or PJI in the non-navigation group. There was no significant difference in the incidence rate of SSI or PJI between the two groups (P = 1.0), although the mean operation time in the navigation group was about 20 min longer. CONCLUSIONS: CT-based hip navigation system may not be associated with SSI or PJI after primary THA, although it prolongs the operation time.

Risk factors for pressure ulcers from the use of a pelvic positioner in hip surgery: a retrospective observational cohort study in 229 patients.

BACKGROUND: Intraoperatively acquired pressure ulcers are serious postsurgical complications requiring additional treatment, reoperation, and extended hospitalization. No study has investigated the frequency of the ulcers caused by compression with a pelvic positioner, which is used in hip surgeries to stabilize patients in the lateral decubitus position. METHODS: This retrospective study investigated the risk factors and the frequency of the ulcers caused by the use of pelvic positioners in hip surgeries. The records of patients who underwent surgical procedures under general anesthesia at our institution between January 1, 2016 and March 31, 2018 were reviewed. The inclusion criterion for the assessment of risk factors was hip surgery in the lateral decubitus position stabilized by a pelvic positioner. The exclusion criteria were patients with trauma, missing data, or a pre-existing pressure ulcer. Finally,.the study included 229 patients (265 hip surgeries). All the patients were positioned in the lateral decubitus position with the assistance of either a pelvic positioner, which had a single support fixture located over the pubic symphysis or a double support fixture located over the bilateral anterior superior iliac spine. Intraoperatively acquired pressure ulcers were diagnosed when ulcers were absent on admission and the redness that was observed immediately after surgery remained after 24 h. Multivariate analysis was used to identify factors associated with an increased risk for ulcers. RESULTS: Ulcers developed in 8 of 1810 (0.44%) patients who underwent orthopedic surgery. Seven of the 265 (2.64%) patients who underwent hip surgery in the lateral decubitus position stabilized by a pelvic positioner developed ulcers. All ulcers were located on areas of the body that were compressed by the pelvic positioner. After identifying controls for patient height (less than 154 cm), surgery duration (longer than 180 min), blood loss (more than 355 ml), and type of pelvic positioner used, we identified the independent risk factors for ulcers to be patient height < 154 cm (adjusted odds ratio, 12.8; p-value, 0.032) and the use of pelvic positioners with pubic bone support (adjusted odds ratio, 10.53; p-value, 0.047). CONCLUSION: The use of pelvic positioners with pubic bone support should be avoided in patients with a height of < 154 cm to decrease the risk of ulcers.