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1.
J Exp Orthop ; 11(3): e12031, 2024 Jul.
Article En | MEDLINE | ID: mdl-38741903

Purpose: Thermoelastic stress analysis (TSA) was used to evaluate stress changes over the entire surface of a specimen. This study aimed to assess the relationship between femoral stress distribution, analysed using TSA and changes in bone mineral density (BMD) after total hip arthroplasty (THA). Methods: Stress changes in the simulated bone before and after taper-wedge stem insertion were measured using the TSA. Stress changes were compared with BMD changes around the stem 1 year after surgery in a THA patient (58 hips) with the same taper-wedge stem. Subsequently, we compared the correlation between stress changes and BMD changes. Results: TSA revealed significant stress changes before and after stem insertion, with prominent alterations in the proximal medial region. The BMD changes at 1 year post-THA exhibited a 15%-25% decrease in the proximal zones, while Zones 2-6 showed a -6% to 3% change. Notably, a strong positive correlation (0.886) was found between the stress change rate and BMD change rate. Conclusions: This study demonstrated a high correlation between femoral stress distribution assessed using TSA and subsequent BMD changes after THA. The TSA method offers the potential to predict stress distribution and BMD alterations postsurgery, aiding in implant development and clinical assessment. Combining TSA with finite element analysis could provide even more detailed insights into stress distribution. Level of Evidence: Case series (with or without comparison).

2.
BMC Musculoskelet Disord ; 25(1): 352, 2024 May 03.
Article En | MEDLINE | ID: mdl-38702633

BACKGROUND: Recent advancements in and the proliferation of autonomous mobility technology, such as intelligent wheelchairs, have made it possible to provide mobility services for patients with reduced mobility due to musculoskeletal disorders. In the present study, we conducted a preliminary clinical study to assess the safety and feasibility of in-hospital autonomous transportation using a driverless mobility (wheelchair) for patients with musculoskeletal disorders. METHODS: From January to February 2022, 51 patients with musculoskeletal disorders exhibiting gait disturbance who presented to our institution were included in the present study. Driverless mobility rides were conducted over a straight-line distance of 100 m from the orthopaedic outpatient reception to the payment counter after the outpatient consultation. We assessed the quality of life using an EQ-5D-5 L index and pain using a VAS score before riding the mobility to investigate the patient's condition. After the ride, a questionnaire survey was conducted to assess patient satisfaction on a 5-point scale. In addition, adverse events during the mobility ride were investigated. RESULTS: Overall satisfaction levels showed that 44 out of 51 (86%) patients rated the level as 3 or higher. There were no significant differences in the level of satisfaction based on the cause of disorders or EQ-5D-5 L Index. Among 19 patients who rated the level of satisfaction as 2-3, the ratio of postoperative patients and those with pain tended to be higher (p < 0.05). While 26 of 51 (51%) patients reported moments of feeling unsafe during the mobility ride, no actual adverse events, such as collisions, were observed. CONCLUSIONS: An in-hospital autonomous transportation service using a driverless mobility for patients with musculoskeletal disorders demonstrated high satisfaction levels and was safe with no severe adverse events observed. The expansion of autonomous mobility deployment is expected to achieve mobility as a service in medical care.


Feasibility Studies , Musculoskeletal Diseases , Patient Satisfaction , Humans , Male , Musculoskeletal Diseases/therapy , Musculoskeletal Diseases/physiopathology , Musculoskeletal Diseases/diagnosis , Female , Middle Aged , Adult , Aged , Quality of Life , Wheelchairs , Transportation of Patients/methods , Mobility Limitation , Surveys and Questionnaires , Aged, 80 and over
3.
J Orthop Surg Res ; 18(1): 664, 2023 Sep 06.
Article En | MEDLINE | ID: mdl-37674224

BACKGROUND: In nerve transfer for peripheral nerve injury, it is sometimes necessary to suture size-mismatched nerves. In 1993, a favorable suture method called the Ochiai suture method for size-mismatched nerve transfer was reported. However, there is currently a lack of substantial evidence beyond the original report. Therefore, this study aimed to verify the advantages of using the Ochiai suture method for size-mismatched nerve transfer. METHODS: A total of 18 rats were evaluated in this study and randomly divided into two groups. All rats underwent femoral to sciatic nerve transfer. Specifically, group A (n = 10) underwent the Ochiai suture method, while group B (n = 8) underwent the perineural suture method. After 12 weeks postoperatively, we conducted the sciatic functional index (SFI) test, measured muscle wet-weight, and performed histological evaluations. All data were compared between the two groups, with Welch's t test for normally distributed data and Mann-Whitney's U test for non-normally distributed data. Statistical significance was set at p < 0.05. RESULTS: The mean number of axons was significantly greater in group A than in group B at 5 mm distal to the stump (p = 0.04). Additionally, the average axonal diameter was significantly greater in group A than in group B at 5 mm and 10 mm distal to the stump (p < 0.01 and p < 0.01, respectively). However, the SFI test and measured muscle wet-weight values showed no significant differences between the two groups. CONCLUSIONS: Our study revealed that the Ochiai suture method for size-mismatched nerve transfer in rats increases the regenerative axon numbers and diameters. These findings suggest that the Ochiai suture method could be a valuable approach for achieving effective motor function restoration in cases of size-mismatched nerve transfer.


Nerve Transfer , Animals , Rats , Neurosurgical Procedures , Sutures , Femur , Muscles
4.
J Pediatr Orthop B ; 2023 May 22.
Article En | MEDLINE | ID: mdl-37266936

This preliminary study investigated the efficacy and safety of bone marrow-derived mesenchymal stem cell transplantation in a piglet Legg-Calve-Perthes disease (LCPD) model. The LCPD model was induced in two Landrace piglets (6- and 7-week-old, weighing 12 and 17 kg, respectively) by ligaturing the femoral neck. In the first piglet, the natural LCPD course was observed. In the second piglet, 4 weeks after ligaturing the femoral neck, simple medium and medium containing 2.44 × 107 bone marrow-derived mesenchymal stem cells were transplanted into the right and left femoral heads after core decompression, respectively. Plain radiographs were obtained every 4 weeks, and the epiphyseal quotient was calculated by dividing the maximum epiphysis height by the maximum epiphysis diameter. The piglets were sacrificed at 14 weeks postoperatively. The femoral heads were extracted and evaluated grossly, pathologically, and by using computed tomography. The transplanted cell characteristics were evaluated using flow cytometry. Flattening of the epiphysis was observed in both femoral heads of the first piglet and only in the right hip of the second piglet. The epiphyseal quotients immediately and at 14 weeks postoperatively in the right femoral head of the second piglet were 0.40 and 0.14, respectively, while those of the left femoral head were 0.30 and 0.42, respectively. Hematoxylin and eosin staining did not reveal physeal bar or tumor cell formation. The transplanted cells were 99.2%, 65.9%, 18.2%, and 0.16% positive for CD44, CD105, CD29, and CD31, respectively. Core decompression combined with bone marrow-derived mesenchymal stem cell transplantation prevented epiphyseal collapse.

5.
Arthroplast Today ; 21: 101140, 2023 Jun.
Article En | MEDLINE | ID: mdl-37151402

Background: Primary stability of the femoral stem is important for the long-term results of cementless total hip arthroplasty. Cementless collared stems have been known to have higher stability than collarless stems when there is a contact between the collar and the calcar. The purpose of this study was to compare the stabilities of collared stem and collarless stem in 2 loading conditions: 1) flat walking and 2) stair climbing. Methods: We constructed 3 finite element models. In the first model, the collar had contact with the calcar. The second model had a 1 mm gap between the calcar and the collar. The third model was constructed with a collarless stem. The proximal femur around the stem was divided into 3 zones: the upper zone (Gruen zones 1 and 7), the middle zone (Gruen zones 2 and 6), and the lower zone (Gruen zones 3 and 5). The micromotion at the stem/bone interface was measured at each zone of the 3 models under the 2 loading conditions. Results: The results showed that collared stems were more stable when the collar was in contact with the calcar than when a gap was left between the collar and the calcar. In particular, collar contact was highly effective in suppressing the micromotion proximal to the stem. Conclusions: Compared to the collarless stem, the collared stem had comparable stability when there was a gap at the collar and calcar interface and higher stability when there was contact between the collar and the calcar.

6.
Orthop Surg ; 15(6): 1664-1669, 2023 Jun.
Article En | MEDLINE | ID: mdl-37092528

OBJECTIVE: During total hip arthroplasty (THA), both pelvic and femur positions affect leg length (LL) and offset (OS) measurements because LL and OS calipers depend on the fixed reference points on the pelvis and femur, respectively. However, LL and OS measurement errors because of pelvic positional changes have not been described. This study aimed to clarify the effects of pelvic positional changes on LL and OS measurements in relation to the pelvic reference using a THA simulator. METHODS: We developed an experimental THA simulator using Sawbones models of the hemipelvis and femur that facilitated modification of the obliquity, tilt, and rotation of the pelvis. Using an LL and OS caliper, LL and OS measurement errors due to pelvic positional changes were determined with the femoral position fixed. Measurements were performed from two pelvic reference positions: the iliac tubercle (P1) and the top of the iliac crest intersecting the line of the femoral long axis (P2). RESULTS: Concerning pelvic obliquity, the total error of LL was 25.0 mm in P1 and 26.5 mm in P2, while the total error of OS was 13.0 mm in P1 and 10.9 mm in P2. For pelvic tilt, the total error of LL was 9.0 mm in P1 and 3.8 mm in P2, while the total error of OS was 0.5 mm in P1 and 1.0 mm in P2. Regarding pelvic rotation, the total error of LL was 13.8 mm in P1 and 3.2 mm in P2, while the total error of OS was 3.8 mm in P1 and 4.0 mm in P2. CONCLUSIONS: Pelvic positional changes alter LL and OS measurements. The acceptable range (error <2 mm) on LL and OS measurement errors of pelvic obliquity was only 2°, regardless of the pelvic reference position. The pelvic reference position should be at the top of the iliac crest intersecting the line of the long axis of the femur because of a small LL measurement error with pelvic tilt and rotation.


Arthroplasty, Replacement, Hip , Bone Diseases , Humans , Leg/surgery , Pelvis , Lower Extremity/surgery , Femur/surgery , Bone Diseases/surgery
7.
Eur J Orthop Surg Traumatol ; 33(2): 441-447, 2023 Feb.
Article En | MEDLINE | ID: mdl-35103855

PURPOSE: This study evaluated the efficacy and safety of a novel treatment for osteonecrosis, in which concentrated autologous bone marrow aspirate transplantation (CABMAT) is followed by low-intensity pulsed ultrasound (LIPUS) stimulation for 3 months. The study was designed as a prospective, uncontrolled, open-label phase II clinical study. METHODS: This study included 16 cases of osteonecrosis of the femoral head (ONFH), including 26 hips. Patients were transplanted with concentrated bone marrow and periodically evaluated for infection and neoplasm development. Moreover, clinical and radiological examinations were conducted to confirm the treatment efficacy. RESULTS: No infections were observed during the course of this study nor tumours developed at the treatment site 24 months after transplantation. At a mean 48 (30-56) months post-transplantation, the onset or progression of collapse was noted in four hips, of which one hip underwent total hip arthroplasty. CONCLUSION: Treatment with CABMAT combined with 3-month LIPUS stimulation was safe, and further randomised clinical studies are needed to determine the efficacy and feasibility of this treatment. TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN000020940, 9/2/2016).


Bone Marrow , Femur Head Necrosis , Humans , Bone Marrow/pathology , Bone Marrow Transplantation , Femur Head/surgery , Femur Head/pathology , Femur Head Necrosis/surgery , Femur Head Necrosis/pathology , Prospective Studies , Transplantation, Autologous , Treatment Outcome
8.
J Surg Case Rep ; 2022(10): rjac478, 2022 Oct.
Article En | MEDLINE | ID: mdl-36285172

Tumor-induced osteomalacia (TIO) is a rare tumor-associated syndrome in which osteomalacia is induced by a tumor. A 67-year-old male patient presented for the first time with low back pain, weakness of the lower extremities and difficulty in walking. Six years earlier, he had nonspecific symptoms such as low back pain, and blood tests showed high alkaline phosphatase and low phosphorus. In addition, fibroblast growth factor 23 (FGF23) was abnormally high at 454 pg/mL. A diagnosis of FGF23-related hypophosphatemic osteomalacia was made. Somatostatin receptor scintigraphy, venous sampling and MRI were performed to localize and diagnose TIO. The tumor was found to be confined to the right femoral head and hemiarthroplasty was performed. Pathological examination revealed a phosphaturic mesenchymal tumor. Postoperatively, symptoms and blood test data improved. Although resection of the lesion and osteochondral transplantation or total hip arthroplasty were considered, hemiarthroplasty was chosen over concerns about treatment failure due to seeding.

9.
J Surg Case Rep ; 2022(10): rjac477, 2022 Oct.
Article En | MEDLINE | ID: mdl-36285171

We present a case of a 42-year-old obese female with a body mass index of 38.4 kg/m2. Laparoscopic tumor resection of a left nonfunctioning adrenal tumor was performed in the lateral jackknife position, and the operative time was over 5 h. After awakening, she complained right buttock pain, and we suspected bursitis due to the surgical position and decided to follow up the patient. On the second postoperative day, spontaneous pain worsened, and the computed tomography scan of the hip showed significant swelling of the gluteal muscles, which led us to suspect a gluteal compartment syndrome. Intramuscular compartment pressure was measured under general anesthesia at 72 mmHg, and a fasciotomy was performed. The symptoms improved promptly after surgery and completely disappeared 2 months after surgery. Although the gluteal compartment syndrome is a rare condition in which circulation is impaired by compression of the gluteal muscles, treatment should be initiated promptly before serious complications arise.

10.
Indian J Orthop ; 56(7): 1251-1258, 2022 Jul.
Article En | MEDLINE | ID: mdl-35813540

Purpose: Since 2003, a hip-preserving technique-concentrated autologous bone marrow aspirate transplantation (CABMAT)-has been applied to treat osteonecrosis of the femoral head (ONFH). We investigated intraoperative and postoperative outcomes of total hip arthroplasty (THA) in patients who underwent CABMAT as hip-preserving surgery for ONFH but developed secondary hip osteoarthritis after progressive femoral head collapse. Methods: A total of 456 hips in 282 patients underwent CABMAT in our hospital between April 2003 and December 2018; 108 hips required THA (THA conversion rate, 23.7%). We enrolled 60 hips (26 hips in 20 men and 34 in 26 women) with a follow-up of over 2 years. We retrospectively analyzed patient background data, time to THA, surgical procedure, postoperative complications, and clinical outcomes from medical records. Results: The disease was steroid-related, alcohol-related, and idiopathic in 48, seven, and five hips, respectively. The mean age at THA was 45.7 years, and mean conversion time was 2.7 years. Cementless THA was performed in all cases; the mean operating time and blood loss were 82.7 min and 210 g, respectively. Postoperative complications were observed in four cases; intraoperative fracture, two cases; superficial infection, one case; and dislocation, one case. The mean follow-up period was 5.7 years; no loosening or deep infections occurred. No patients required revision arthroplasty. Conclusion: We noted no complications related to CABMAT. After a minimum 2-year follow-up, the clinical outcomes were good. CABMAT was found to be an useful hip-preserving surgery, with little effect on conversion to THA, and THA outcomes were good.

11.
Cureus ; 14(5): e24658, 2022 May.
Article En | MEDLINE | ID: mdl-35663701

Purpose The purpose is to compare the therapeutic efficacy of concentrated autologous bone marrow aspirate transplantation (CABMAT) with that of observation alone for osteonecrosis of the femoral head (ONFH). Methods This single-center study included patients with idiopathic ONFH that were either treated with CABMAT (CABMAT group) or managed through observation alone (observation group) over a >2-year follow-up period. The Japanese Investigation Committee classification was used to diagnose and classify ONFH. The collapse rates for stages 1 and 2 ONFH (i.e., pre-collapse stages) and the THA conversion rates were compared between the CABMAT and observation groups. Results The CABMAT and observation groups comprised 232 (mean follow-up: 8.2 years) and 106 (mean follow-up: 6.0 years) patients, respectively. No significant intergroup differences were noted in the stages, types, and associated factors of ONFH. The collapse rates for pre-collapse stages in the CABMAT and observation groups were 67.1% and 65.3%, respectively. For stage 1, the collapse rates were significantly lower in the observation group than in the CABMAT group (p<0.05). The overall THA conversion rates in the CABMAT and observation groups were 24.3% and 41.5%, respectively (p<0.0001). For ONFH of stages 3A and 3B (collapse stages), the THA conversion rates were significantly lower in the CABMAT group (p<0.05). Conclusion Collapse rates were significantly higher for stage 1 ONFH; for collapse stages, the THA conversion rates were significantly lower in the CABMAT group than in the observation group. Therefore, observation and CABMAT are recommended for ONFH of stage 1 and for ONFH of higher stages, respectively.

12.
Arthroplast Today ; 13: 188-193, 2022 Feb.
Article En | MEDLINE | ID: mdl-35118182

Antibiotic-loaded acrylic cement beads have a large surface area and excellent sustained-release properties. However, there are some difficulty manufacturing reasonably sized beads and their careful handling. We developed a self-made cement bead maker using a mold of a sphere with a diameter of 8 and 10 mm with a 2-mm-diameter connecting hole. With this instrument, approximately 32 beads can be made from 40 g of bone cement. We clinically applied this technique to 11 cases of periprosthetic joint infection. There was no recurrence of infection noted. The advantages of this device were that it was possible to adjust the combination of antimicrobial agents and that the shape was uniform and easy to handle during surgery.

13.
Acta Bioeng Biomech ; 24(2): 47-54, 2022.
Article En | MEDLINE | ID: mdl-38314493

PURPOSE: The aim of this study was to evaluate the stress distribution in a synthetic femur that was implanted with a fully hydroxyapatite-coated stem using thermoelastic stress and finite element analyses, and to clarify the differences in the stress distributions between these two methods. METHODS: Thermoelastic stress analysis is a stress-analysis technique that employs the thermoelastic effect. Sinusoidal vertical loads were applied to the head of the stem placed on the synthetic femur, and surface stress distribution images were acquired using an infrared stress measurement system. The finite element model for the synthetic femur and stem were set up similarly to the thermoelastic stress analysis experiment, and vertical load was applied to the head of the stem. Surface stress distribution and stress values obtained via these two methods were compared. RESULTS: Thermoelastic stress analysis showed that compressive and tensile stresses were distributed from the proximal femur to the diaphysis, not only on the medial and lateral surfaces, but also on the anterior and posterior surfaces. However, finite element analysis showed that compressive stress was not distributed on the anterior and posterior surfaces of the femoral intertrochanter. The stress values of thermoelastic stress analysis tended to be higher in the proximal femur than that obtained via the finite element analysis. CONCLUSIONS: The surface stress distribution obtained by these two methods were different specifically in the proximal femur. Our results imply that thermoelastic stress analysis has a better potential than finite element analysis to show the surface stress distribution that reflects the stem design.

14.
J Med Case Rep ; 15(1): 607, 2021 Dec 22.
Article En | MEDLINE | ID: mdl-34933668

BACKGROUND: Femoral neck stress fractures are rare and often recognized as overuse injuries that occur in young athletes or military personnel. A case following osteonecrosis of the femoral head is quite rare; even more uncommon is its occurrence in the bilateral hips. Magnetic resonance imaging has been established as the preferred tool for diagnosing nondisplaced femoral neck stress fracture due to overuse injury. Magnetic resonance imaging was also useful to detect the initial lesion even in this case, although the etiology was different between overuse injury and insufficiency fracture. CASE PRESENTATION: A 41-year-old Japanese woman diagnosed with bilateral early stage idiopathic osteonecrosis of the femoral head was observed non-weight-bearing as much as possible using a stick. However, her pain and difficulty in walking progressed. Bilateral femoral neck stress fractures were subsequently detected by magnetic resonance imaging. The fracture initially appeared as a spot of bone marrow edema at the medial site of the femoral neck, and then developed into a fracture line. The patient underwent internal fixation of both hips with sliding hip screws to stabilize the stress fractures. In addition, the preparatory reaming served as core decompression of the femoral heads, as well as being treatment for osteonecrosis. Her bone mineral density and 25-hydroxy vitamin D values were low for her age. We administered eldecalcitol and teriparatide acetate. Her symptoms mostly improved, and the fracture lines and necrotic lesions on magnetic resonance imaging reduced at 5 months after the surgery. CONCLUSIONS: Bilateral femoral neck stress fractures are a very rare condition and are often missed. It is important to listen to the patient's complaints and perform an appropriate examination. We encountered a case of bilateral femoral neck stress fracture that occurred in a patient with early stage osteonecrosis of the femoral head, and were able to observe progression of stress fracture since before fracture occurred. This is considered to be the first report to capture imaging changes before and after the onset.


Femoral Neck Fractures , Fractures, Stress , Osteonecrosis , Adult , Female , Femoral Neck Fractures/diagnostic imaging , Femoral Neck Fractures/surgery , Femur Head , Femur Neck , Fracture Fixation, Internal , Fractures, Stress/diagnostic imaging , Fractures, Stress/surgery , Humans
15.
Tomography ; 7(4): 734-746, 2021 11 04.
Article En | MEDLINE | ID: mdl-34842826

Venous thromboembolism (VTE) is a severe complication in orthopedic surgeries. Herein, we developed a novel leg exercise apparatus (LEX) to encourage postoperative limb movement in bedridden patients to prevent VTE. We aimed to evaluate its feasibility and safety in individuals at risk of VTE. Twenty patients (four men, 16 women) who underwent total joint arthroplasty in the lower extremity were enrolled in this prospective study. Exercise using the LEX was performed for 5 min at 30 cycles/min, four times/day during postoperative days 1-7. Clinical assessments included the evaluation of vital signs, venous ultrasonography, and blood tests within seven days postoperatively, and adverse events (pulmonary embolism and cerebral hemorrhage) were monitored. Overall, 16/20 (80%) patients completed the 7-day exercise regimen. There were no cases of severe adverse events, changes in vital signs, or lower-extremity deep vein thrombosis in patients who performed exercises with the LEX. Thus, the results of this pilot study show that this novel apparatus may be a safe and feasible tool for VTE prophylaxis after joint arthroplasty of the lower extremities.


Venous Thromboembolism , Arthroplasty/adverse effects , Feasibility Studies , Female , Humans , Leg , Lower Extremity/blood supply , Lower Extremity/diagnostic imaging , Male , Pilot Projects , Prospective Studies , Venous Thromboembolism/diagnostic imaging , Venous Thromboembolism/etiology , Venous Thromboembolism/prevention & control
16.
Diagnostics (Basel) ; 11(11)2021 Nov 12.
Article En | MEDLINE | ID: mdl-34829440

Digital tomosynthesis (DTS) is a new imaging technique derived from radiography, and its usefulness has been gradually reported in the field of orthopedic diagnosis in recent years. A fully hydroxyapatite (HA)-coated stem, which is used for total hip arthroplasty (THA), is a type of cementless stem that has been widely used recently and reported to have good results. However, stem loosening on plain radiographs is difficult to determine in some cases due to cancellous condensation around the stem. In this retrospective cross-sectional study, we compared the results of plain radiography versus DTS to evaluate the imaging findings after THA using a fully HA-coated stem. Twenty joints each in the 3 y and 1 y postoperative groups underwent plain radiography and DTS. On DTS, bone formation around the stem was confirmed in all cases; however, this formation was not reproducible on plain radiography, and there were cases in which the reaction could not be confirmed or cases with cancellous condensation resembling reactive lines. This reaction was not reproducible on plain radiographs, and in some cases, the reaction could not be confirmed, or there were cases with cancellous condensation that resembled reactive lines. Therefore, DTS was useful in the diagnosis of bone formation around the implant.

17.
J Rural Med ; 16(2): 83-90, 2021 Apr.
Article En | MEDLINE | ID: mdl-33833833

Objective: In this study, thermoelastic stress analysis was conducted to clarify the surface stress distribution of a femur in which a BiCONTACT E stem was inserted. The contact sites between the stem and femur were examined to investigate the association with the range of stress distribution. Materials and Methods: BiCONTACT E was set up using two synthetic femurs that mimic the morphology and mechanical properties of living bone. Preoperative planning was performed using three-dimensional imaging software. The synthetic bone was placed in a sample holder. After the stem was implanted into the synthetic bone, computed tomography imaging was performed. The contact sites between the stem and the cortical part of the synthetic bone were examined using the imaging software. Subsequently, thermoelastic stress measurements were performed on the sample. Results: The results of thermoelastic stress analysis indicated a minimum change in the sum of principal stresses [Δ (σ1+σ2)] on the medial side and a maximum change in the sum of principal stresses on the lateral side. Thus, no minimum change was observed in the sum of the principal stresses at the maximum proximal part. It is reasonable to assume that the use of a cementless stem can inevitably lead to bone atrophy in the proximal part of the femur. The contact sites between the stem and femur were also investigated, and the results of the study clearly and quantitatively demonstrated the correlation of the contact sites with a range of stress distributions. Conclusion: The surface stress distribution of a femur, in which a BiCONTACT E stem was inserted, was clarified. The contact sites between the stem and femur were also investigated. Furthermore, the correlation between these results and clinical bone response was investigated in this study.

18.
J Orthop Surg Res ; 16(1): 193, 2021 Mar 16.
Article En | MEDLINE | ID: mdl-33726774

BACKGROUND: Leg length (LL) and offset (OS) are important factors in total hip arthroplasty (THA). Because most LL and OS callipers used in THA depend on fixed points on the pelvis and the femur, limb position could affect measurement error. This study was conducted on a THA simulator to clarify the effects of lower limb position and iliac pin position on LL and OS errors and to determine the permissible range of limb position for accurate LL and OS measurement. METHODS: An LL and OS measurement instrument was used. Two pin positions were tested: the iliac tubercle and the top of the iliac crest intersecting with the extension of the femoral axis. First, the limb was moved in one direction (flexion-extension, abduction-adduction, or internal-external rotation), and LL and OS were measured for each pin position. Next, the limb was moved in combinations of the three directions. Then, the permissible range of combined limb position, which resulted in LL and OS measurement error within ±2 mm, was determined for each pin position. RESULTS: Only 4° of abduction/adduction caused 5-7 mm error in LL and 2-4 mm error in OS, irrespective of pin position. The effects of flexion-extension and internal-external rotation on LL error were smaller for the top of the iliac crest than for the iliac tubercle, though OS error was similar for both pin positions. For LL, the permissible range of the combined limb position was wider for the top of the iliac crest than for the iliac tubercle. CONCLUSION: To minimize LL and OS measurement errors in THA, adduction-abduction must be maintained. The iliac pin position in the top of the iliac crest is preferred because it provides less LL measurement error and a wider permissible range of combined limb position for accurate LL measurement.


Arthroplasty, Replacement, Hip/methods , Bone Nails , Leg Bones/anatomy & histology , Lower Extremity , Pelvis , Arthroplasty, Replacement, Hip/adverse effects , Humans , Leg Length Inequality/etiology , Models, Anatomic
19.
J Rural Med ; 16(1): 1-7, 2021 Jan.
Article En | MEDLINE | ID: mdl-33442428

Objective: To compare the outcomes of steroid-associated osteonecrosis of the femoral head in patients with systemic lupus erythematosus who underwent conservative treatment and concentrated autologous bone marrow aspirate transplantation Methods: Osteonecrosis of the femoral head was classified according to the Japanese Investigation Committee system. Concentrated autologous bone marrow aspirate transplantation was performed by aspirating the bone marrow from both iliac crests and then transplanting it to the necrotic area after the core decompression. Patients with >2-year follow-up after the concentrated autologous bone marrow aspirate transplantation in our institution (Group I) and those with >2-year follow-up after the first hospital visit in a cooperative institution (Group II) were included in this study. After a randomized matching based on age, sex, type, stage, and etiology, the collapse rate in pre-collapsed stages and total hip arthroplasty conversion rate in all stages were compared between the two groups. Results: After the matching adjustment, 33 pairs of hips were included. Preoperatively, 1, 2, 16, and 14 hips were classified as types A, B, C1, and C2, respectively, and 15, 13, 2, and 3 hips were classified as stages 1, 2, 3A, and 3B, respectively. The collapse rates in the pre-collapsed stages were 68% and 39% in Groups I and II, respectively. Total hip arthroplasty conversion rates were 33% and 45% in Groups I and II, respectively. However, Group I had significantly higher and lower conversion rates in stages 1 and 3, respectively (both P<0.05). Conclusion: Conservative treatment may be preferable in stage 1 hips. In addition, concentrated autologous bone marrow aspirate transplantation may prevent further collapse in stage 3.

20.
Case Rep Orthop ; 2020: 4218719, 2020.
Article En | MEDLINE | ID: mdl-32395361

Stress fractures following total hip arthroplasty in the lower limbs away from the surgical area are very rare. We report a case of stress fracture in the isolated distal fibula that presented five months after total hip arthroplasty in a patient with developmental dysplasia of the hip. A 67-year-old woman diagnosed with coxarthrosis of the right hip joint, classified as Crowe's group 3, underwent total hip arthroplasty with acetabular reconstruction using a bulk bone graft. The surgery successfully treated the preoperative leg length discrepancy and flexion and external rotation contractures. The alignment of the right lower limbs changed from slight varus to valgus knee following surgery. The postoperative process went well; however, she experienced lateral ankle pain on the affected side five months after surgery. No obvious fracture was observed via radiograph; however, she received a subsequent diagnosis of isolated distal fibula stress fracture. Additionally, she was diagnosed with vitamin D deficiency. Valgus alignment change of the knee joint and vitamin D deficiency were considered the main causes of the stress fracture. Stress fractures should be suspected in patients complaining of unexpected pain following total hip arthroplasty, even in distant areas of the affected limb, especially in osteoporotic patients.

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