Initial Rotational Instability of the Tapered Wedge-Shaped Type Cementless Stem.

BACKGROUND: Because the tapered wedge-shaped type cementless stem has a small anteroposterior width and a low occupation rate in the medullary space, postoperative rotational instability and stem subsidence due to inadequate proximal fixation are concerns. The purpose of this study was to clarify the relationship between the rotational instability of the tapered wedge-shaped type cementless stem and femoral canal shape. METHODS: A total of 61 primary total hip arthroplasties with the tapered wedge-shaped type cementless stem Accolade® TMZF (11 males, 50 females; mean age 60 years) from January 2012 to June 2015 who underwent computed tomography before surgery and within 4 weeks and 1 year after surgery were evaluated. The preoperative femoral neck anteversion angle, preoperative femoral canal flair index, the degree of postoperative stem subsidence within 1 year after operation, and the degree of rotational change in the stem setting angle within 1 year after operation were investigated. RESULTS: The mean preoperative femoral neck anteversion angle was 32.2° ± 17.8° (0°-69°), and the mean preoperative canal flair index was 3.68 ± 0.58 (2.44-5.55). There were no stem subsidence cases within 1 year after operation. The mean degree of rotational change in the stem from immediately to 1 year after surgery was -0.4° ± 1.7° (-3°-3°). There was no significant correlation between the canal flair index and the rotational change in the stem. In addition, the mean difference between the preoperative femoral neck anteversion angle and the stem rotational angle immediately after surgery was only 1.3° ± 5.3° (-29°-15°). CONCLUSIONS: In all cases, including stove-pipe cases, the degree of rotational change in the Accolade® TMZF stem from immediately to 1 year after surgery was within 3°. In other words, regardless of femoral canal shape, the tapered wedge-shaped type cementless stem has little initial rotational instability.

The Differences in Imaging Findings Between Painless and Painful Osteoarthritis of the Hip.

PURPOSE: In osteoarthritis of the hip, the pain may be strong even if the deformity is mild, but the pain may be mild even if the deformity is severe. If the factors related to the pain can be identified on imaging, reducing such factors can alleviate the pain, and effective measures can be taken for cases where surgery cannot be performed. In addition, imaging findings related to the pain are also important information for determining the procedures and the timing of surgery. Thus, the purpose of this study was to identify the differences in features of osteoarthritis seen on imaging between painless and painful osteoarthritis of the hip. METHODS: The subjects were the patients with hip osteoarthritis who visited our department in 2015 and who underwent x-ray, computed tomography (CT), and magnetic resonance imaging (MRI), a total of 29 patients (54 hip joints; mean age 63 years; 8 males and 21 females). The degree of osteoarthritis was determined using the Tönnis grade from the x-ray image. The cartilage morphology, intensity changes of bone marrow on MRI (subchondral bone marrow lesions [BMLs]), osteophytes, joint effusions, and paralabral cysts were scored based on the Hip Osteoarthritis MRI Scoring System (HOAMS). The cross-sectional area of the psoas major muscle at the level of the iliac crest was measured on CT, and the psoas index (PI; the cross-sectional area ratio of the psoas major muscle to the lumbar 4/5 intervertebral disc) was calculated to correct for the difference in physique. Then, the relationships between these and visual analog scale (VAS) scores of pains were evaluated. RESULTS: The average VAS was 55.4 ± 39 mm. The PI and all items of HOAMS correlated with the VAS. The average VAS of Tönnis grade 3 osteoarthritis was 75.8 ± 26 mm. When investigating only Tönnis grade 3 osteoarthritis, the differences between cases with less than average pain and those with above average pain were the BML score in the central-inferior femoral head (P = .0213), the osteophyte score of the inferomedial femoral head (P = .0325), and the PI (P = .0292). CONCLUSION: Investigation of the differences between painless and painful osteoarthritis of the hip showed that the cases with more pain have BMLs of the femoral head on MRI that extend not only to the loading area, but also to the central-inferior area. Even with the same x-ray findings, the pain was stronger in patients with severe psoas atrophy. Thus, the instability due to muscle atrophy may also play a role in the pain of hip osteoarthritis.

A Comparison of the Incidences of Venous Thromboembolism after Total Hip Arthroplasty between the Direct Anterior Approach and the Direct Lateral Approach, Especially in the Early Period after Introduction of the Direct Anterior Approach.

OBJECTIVE: To compare the incidence of venous thromboembolism (VTE) after total hip arthroplasty (THA) using the direct anterior approach (DAA) with that using the direct lateral approach (DLA). In addition, patient background characteristics and the incidence of VTE were compared between the first half and the latter half of the period after introducing DAA and against DLA. METHOD: This was a retrospective, multicenter study involving 109 patients (116 hips) who had undergone primary unilateral THA. Thirty-six hips underwent THA using DAA and 80 hips underwent THA using DLA. Patient information including sex, age, and preoperative diagnosis was collected. The incidence of VTE was compared between DAA and DLA. Moreover, the patients who underwent THA using DAA were divided into 2 groups (first half and latter half groups), and sex, age, body mass index (BMI), and surgical time were compared between the 2 groups. Moreover, the incidence of VTE was compared among the 3 groups (first half of DAA, latter half of DAA, and DLA). RESULTS: The incidence of VTE in the DAA group was significantly higher than that in the DLA group (p=0.014). The incidence of VTE in the first half group was significantly higher than in the latter half group and the DLA group (p=0.035 and p=0.001, respectively), and there was no difference in the incidence of VTE between the latter half group and the DLA group (p=0.923). Surgical time was significantly longer in the first half group than in the latter half group (p=0.046). CONCLUSIONS: In the first half of the period after introducing the DAA, more VTEs occurred than in the DLA. It may be important to shorten the surgical time in the early stage of introducing the DAA, and aggressive anticoagulation therapy may be required until the surgeon becomes familiar with the procedure.

The location of the fracture determines the better solution, osteosynthesis or revision, in periprosthetic femoral fractures.

PURPOSE: Periprosthetic femoral fractures are difficult to treat, but few reports have included many periprosthetic femoral fractures. The purpose of this study was to investigate the trends and characteristics of a large number of periprosthetic femoral fractures and to determine the best treatment strategy for such fractures. METHODS: The fracture type according to the Vancouver classification, the stem fixation style of previous surgery, the elapsed time from previous surgery, and the treatment method for periprosthetic fractures of 51 patients with periprosthetic femoral fractures who were seen between 2006 and 2018 were investigated. RESULTS: The types of fractures according to the Vancouver classification were: type A 5.9%, type B1 47%, type B2 20%, type B3 2.0%, and type C 25%. Of the previous surgeries, 76% were cementless fixation, and 24% were cemented fixation. The mean duration from previous surgery to periprosthetic femoral fracture was 8 years and 7 months (1-358 months), and injury within 1 year from previous surgery was most commonly observed (24%). As treatment for periprosthetic femoral fractures, conservative treatment was performed in 8%, and surgery was performed in 92%. Of the surgery cases, 53% underwent osteosynthesis, and 39% underwent revision surgery. Of type B1 surgery cases, 58% were treated with osteosynthesis, and 33% underwent revision surgery, although type B1 had no stem loosening. CONCLUSION: Many periprosthetic femoral fractures occurred within 1 year after the previous surgery. Therefore, preventive measures for periprosthetic femoral fractures should be started immediately after total hip replacement. In addition, revision surgery was performed even if the stem was not loosened in cases where it was judged that sufficient osteosynthesis could not be performed.

Incidence and Clinical Outcomes of Hip Fractures Involving Both the Subcapital Area and the Trochanteric or Subtrochanteric Area.

PURPOSE: Proximal femoral fractures involving both the subcapital area and the trochanteric or subtrochanteric area have rarely been reported, but they are not uncommon. However, few studies have reported the incidence or clinical outcomes of such fractures. This study investigated such fractures. METHODS: In area classification, the proximal femur is divided into 4 areas by 3 boundary planes: the first plane is the center of femoral neck; the second plane is the border between femoral neck and femoral trochanter; and the third plane links the inferior borders of greater and lesser trochanters. A fracture only in the first area is classified as a Type 1 fracture; one in the first and second areas is classified as a Type 1-2 fracture. Therefore, proximal femoral fractures involving both the subcapital area and the trochanteric area are classified as Type 1-2-3, and those involving both the subcapital area and the subtrochanteric area are classified as Type 1-2-3-4. In this study, a total of 1042 femoral proximal fractures were classified by area classification, and the treatment methods and the failure rates were investigated only for Types 1-2-3 and 1-2-3-4 cases. The failure rate was defined as the incidence of internal fixator cut-out or telescoping >10 mm. RESULTS: Types 1-2-3 and 1-2-3-4 fractures accounted for 1.72%. Surgical treatment was performed for 89%. Of these, 56% underwent osteosynthesis, but the failure rate was 33%. The other patients (44%) underwent prosthetic replacement. Fracture lines of all these fractures were present along trochanteric fossa to intertrochanteric fossa in posterior aspect and just below the femoral head in anterior aspect. CONCLUSION: Fracture involving the subcapital area to the trochanteric or subtrochanteric area was found in approximately 2%. In patients for whom prosthetic replacement was selected, good results were obtained. However, 1/3 of patients who underwent osteosynthesis had poor results.

Relationship between clinical results of total hip replacement and postoperative activities including weeding and snow shovelling.

INTRODUCTION: Weeding or snow shovelling is indispensable for life in farm villages of northern countries. Clarifying the relationships between the degrees of these activities after total hip replacement (THR) and the clinical results of THR may enable us to predict the results of THR for high-level activity patients. The relationships between work activities after THR and the results were investigated. METHODS: The subjects were 95 post-THR patients, who consulted 6 hospitals in August 2012. First, the Japanese Orthopaedic Association Hip-Disease Evaluation Questionnaire (JHEQ) and a questionnaire on postoperative activity were administered. Then, the Japanese Orthopaedic Association hip score (JOA score) was evaluated. RESULTS: The subjects' average age was 68 years. The average period after surgery was 4 years and 5 months. Weeding and snow shovelling were performed after THR in 44.2% and 40.0% of cases, respectively. The rate of farming after surgery (25.6%) was greater than that of swimming (21.1%). Both the JOA score and JHEQ were higher in those who played sports after THR than in those who did not (p = 0.003, p = 0.0046). The JOA score of those who performed work activities after THR was higher than that of those who did not (p = 0.0295). CONCLUSIONS: Nearly half of patients performed weeding or snow shovelling after THR, and about 1/4 of the patients engaged in farming after THR. The clinical results in cases doing sports and work activities after THR were better than those of cases not doing such activities. Therefore, these activities may be positively recommended.

A Case of Fracture-Redislocation of the Hip Caused by a Depressed Fracture of the Femoral Head Similar to a Hill-Sachs Lesion.

The present case shows a case of fracture-redislocation of the hip caused by a depressed fracture of the femoral head similar to a Hill-Sachs lesion. A 59-year-old man fell from a roof and his left hip joint was dislocated posteriorly. He was admitted to a nearby hospital, and he was referred to our hospital more than 24 hours after injury. Computed tomography (CT) suggested a bone chip from the posterior wall of the acetabulum roof and a depressed femoral head that cut into the posterior margin of the acetabulum roof. Immediate manual repositioning was performed under general anesthesia on the same day. He left our hospital to go home on day 26 after repositioning, but his left hip joint was dislocated again when he went down the stairs. It was thought that this patient's redislocation occurred due to a femoral head depressed fracture involving the same mechanism as the Hill-Sachs injury seen with dislocation of the shoulder. The remplissage method for the Hill-Sachs injury is difficult for the femoral head. Therefore, total hip replacement was performed, and the patient's postoperative course was good. We conclude that total hip arthroplasty should be considered as one of the best treatment methods for such cases.

The choice of internal fixator for fractures around the femoral trochanter depends on area classification.

PURPOSE: In femoral trochanteric fractures, fractures whose fracture lines extend to the basal neck or to the subtrochanteric part have high instability. Area classification can identify such instable fractures. The best choices of internal fixators for femoral trochanteric fractures were investigated according to area classification. METHODS: Femoral trochanteric fractures were investigated with respect to area classification. In area classification, the proximal femur is divided into 4 areas with 3 boundary lines: Line-1 is the center of the neck; Line-2 is the border between the neck and the trochanteric zone; and Line-3 links the inferior borders of the greater and lesser trochanters. A fracture in only the third area was classified as type 3; one in the second and third areas was classified as type 2-3. RESULTS: Of 284 femoral trochanteric fractures, 50.0 % were type 3, 21 % were type 2-3, 22 % were type 3-4, and 7.4 % were type 2-3-4. Cases with cut-out or excessive telescoping of the internal fixator were defined as the Failure-group; 5.3 % of type 3 and 10.9 % of type 2-3 were in the Failure-group only when short femoral nails with a single rag screw were used. On the other hand, there were no Failure-group cases of type 2-3 with double rag screws. Only 1 case involved a long nail for type 3, while a long nail was used in about half of type 3-4 cases (Chi square test: P < 0.0001). CONCLUSIONS: A double rag screw should be considered for type 2-3. A long nail should be considered for type 3-4.

The impact of high-frequency magnetic stimulation of peripheral nerves: muscle hardness, venous blood flow, and motor function of upper extremity in healthy subjects.

The purpose of this study was to investigate the impact of high-frequency peripheral nerve magnetic stimulation on the upper limb function. Twenty-five healthy adults (16 men and 9 women) participated in this study. The radial nerve of the non-dominant hand was stimulated by high-frequency magnetic stimulation device. A total of 600 impulses were applied at a frequency of 20 Hz and intensity of 1.2 resting motor threshold (rMT). At three time points (before, immediately after, and 15 min after stimulation), muscle hardness of the extensor digitorum muscle on the stimulated side was measured using a mechanical tissue hardness meter and a shear wave imaging device, cephalic venous blood flow on the stimulated side was measured using an ultrasound system, and the Box and Block test (BBT) was performed. Mechanical tissue hardness results did not show any significant differences between before, immediately after, and 15 min after stimulation. Measurements via shear wave imaging showed that muscle hardness significantly decreased both immediately and 15 min after stimulation compared to before stimulation (P < 0.05). Peripheral venous blood flow and BBT score significantly increased both immediately and 15 min after stimulation compared to before stimulation (P < 0.01). High-frequency peripheral nerve magnetic stimulation can achieve effects similar to electrical stimulation in a less invasive manner, and may therefore become an important element in next-generation rehabilitation.

Ganglioneuroblastoma of filum terminale: case report.

OBJECT: Neuroblastic tumors can be classified as neuroblastoma, ganglioneuroblastoma (GNB), or ganglioneuroma. Ganglioneuroblastomas consist of small, round, immature neuroblast cells and matured ganglion cells. They are most commonly found in the mediastinum and retroperitoneum; intraspinal GNBs are extremely rare. There are only 5 cases of intraspinal GNB reported in the English literature. The authors report a case of GNB of the filum terminale. The duration of follow-up after the initial treatment is longer than in any other published reports. METHODS: A 36-year-old woman underwent resection of an intradural extramedullary tumor at L1-2 in 1993. Pathological diagnosis was GNB. After surgery, her symptoms resolved and she recovered to a normal condition. In 2009, when she was 53 years old, she presented to the hospital with paralysis of both legs. Magnetic resonance imaging suggested recurrence of spinal tumor. She underwent subtotal resection of the tumors, followed by 4 weeks of radiation therapy. RESULTS: Neurological symptoms improved, and, after radiation therapy, the patient was able to walk with a crutch. Histological investigation of the excised tumor indicated that it was a nodular type GNB, which was consistent with the diagnosis from the time of the initial surgery in 1993. Follow-up MRI studies showed no growth of residual tumors in the 3 years following the surgery. CONCLUSIONS: The authors present a rare case of spinal GNB. The duration of follow-up after the initial surgery in 1993 represents the longest description of clinical course after treatment for spinal GNB.

The reliability of classifications of proximal femoral fractures with 3-dimensional computed tomography: the new concept of comprehensive classification.

The reliability of proximal femoral fracture classifications using 3DCT was evaluated, and a comprehensive "area classification" was developed. Eleven orthopedists (5-26 years from graduation) classified 27 proximal femoral fractures at one hospital from June 2013 to July 2014 based on preoperative images. Various classifications were compared to "area classification." In "area classification," the proximal femur is divided into 4 areas with 3 boundary lines: Line-1 is the center of the neck, Line-2 is the border between the neck and the trochanteric zone, and Line-3 links the inferior borders of the greater and lesser trochanters. A fracture only in the first area was classified as a pure first area fracture; one in the first and second area was classified as a 1-2 type fracture. In the same way, fractures were classified as pure 2, 3-4, 1-2-3, and so on. "Area classification" reliability was highest when orthopedists with varying experience classified proximal femoral fractures using 3DCT. Other classifications cannot classify proximal femoral fractures if they exceed each classification's particular zones. However, fractures that exceed the target zones are "dangerous" fractures. "Area classification" can classify such fractures, and it is therefore useful for selecting osteosynthesis methods.