Publications by authors named "Shohei Okahisa"

Background: While cementless short stems have become popular in total hip arthroplasty (THA), Metha is a relatively recent development that differs from other short stems in its initial fixation concept of partial collum-sparing metaphyseal anchorage. The purpose of this study was to quantify the contact state between Metha and the femur. Additionally, we investigated the difference in contact points between Meta and Fitmore, which is one of the more popular curved short stems.

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Background: Posttraumatic patellar dislocation is rare, and consistent surgical strategy therefore has not been defined due to multifactorial factor. In this case study, we treated a case of a patellar dislocation with hip osteoarthritis and increased femoral anteversion by performing a two-staged surgery. In the first stage, total hip arthroplasty was performed, and in the second stage, simultaneous patellofemoral arthroplasty and medial patellofemoral ligament reconstruction using semitendinosus tendon autograft were performed.

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Article Synopsis
  • Unloading the proximal medial femoral cortex during total hip arthroplasty can lead to increased bone strain at the prosthesis's distal part, potentially causing distal femoral cortical hypertrophy (CH) and affecting stress shielding (SS).
  • In a study of 240 patients, CH was observed in 30% of cases, with focal-type found in 9.6% and diffuse-type in 20.4%, while 17.1% experienced SS, mostly developing after the onset of diffuse-type CH.
  • The results suggest a correlation between diffuse-type CH and the deterioration of fixation stability in Bicontact stem implants, indicating the need for careful monitoring post-surgery.
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Article Synopsis
  • * She previously underwent surgery 8 years ago for an intertrochanteric fracture using a dynamic hip screw.
  • * After a successful one-stage total hip arthroplasty (THA), her hip function improved significantly, with the Modified Harris Hip Score rising from 70 to 95 points within a year.
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Purpose: Combined anteversion (CA) technique (stem-first procedure) is generally accepted as the optimal technique to attain an appropriate CA value in total hip arthroplasty (THA). However, cup anteversion is strongly influenced by the native femoral anteversion. Accordingly, anterior protrusion of the cup in the acetabulum might occur.

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Kerboull-type acetabular support rings (KT) and allogenic bone graft were used for severe periacetabular bone loss with primary and revision total hip arthroplasty (THA). The purpose of this case-control study is to evaluate the risk factors related to poor outcomes of surgery.Sixty patients underwent primary THA and revision THA using allogenic bone graft with KT for large acetabular deficiency.

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Purpose: In the combined anteversion (CA) technique for total hip arthroplasty (THA) with a cementless stem, cup anteversion is strongly influenced by the native femoral anteversion. It is hypothesized that in cases with large native femoral anteversion, cup anteversion can be decreased, and anterior cup protrusion from the anterior edge of the acetabulum could occur due to the achievement of optimal CA. In this study, the accuracy of CA in THA with the CA technique using imageless navigation and the relationship between the protrusion of the anterior edge of cup and optimum CA was retrospectively evaluated.

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Rationale: Curved periacetabular osteotomy (CPO) is a procedure with excellent surgical outcome that has been proposed for patients with development dysplasia of the hip (DDH). However, the surgical outcomes depend on the surgeon's experience and proficiency.

Patient Concerns: A 38-year-old female indicated she was experiencing left hip pain while walking.

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In association with the growing interests in pain management, several modalities to control postoperative pain have been proposed and examined for the efficacy in the recent studies. Various modes of peripheral nerve block have been proposed and the effectiveness and safety have been examined for each of those techniques. We have described our clinical experiences, showing that continuous femoral nerve block could provide a satisfactory analgesic effect after total hip arthroplasty (THA) procedure.

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Background: The number of hemodialysis patients has been progressively increasing in our country. On the other hand, chronic hip arthropathy associated with long-term hemodialysis is a devastating problems affecting patients' quality of life. In our previous study, we proposed a classification system for radiological abnormalities seen in hemodialysis-related hip lesions.

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Implant positioning is one of the critical factors that influences postoperative outcome of total hip arthroplasty (THA). Malpositioning of the implant may lead to an increased risk of postoperative complications such as prosthetic impingement, dislocation, restricted range of motion, polyethylene wear, and loosening. In 2012, the intraoperative use of smartphone technology in THA for improved accuracy of acetabular cup placement was reported.

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Implant positioning is one of the critical factors influencing postoperative outcomes in total hip arthroplasty (THA). Several studies have reported that the postoperative antetorsion (AT) measurement for the femoral stem inserted without navigation showed wide variability. The current authors developed a simple instrument, the Gravity-guide (G-guide), for intraoperative assessment of stem AT and adjustment.

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Synovial osteochondromatosis of the hip is a rare condition, and the surgical treatment approach for this condition requires complete removal of loose bodies combined with synovectomy. While these, procedures are generally accepted as the optimal treatment method, this is still controversial topic. Recent studies have reported that open surgical procedures remain acceptable for synovial osteochondromatosis of the hip.

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A 47-year-old man underwent ceramic cup arthroplasty when he was 22 years old. Revision total hip arthroplasty was performed 25 years later because of limited range of motion without implant loosening. Histologic examination revealed that the femoral head and ceramic implant were well fixed through a thin fibrous membrane.

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Purpose: In total hip arthroplasty (THA), combined anteversion (CA) is used as a parameter for assessment of overall prosthetic alignment. The purpose of this study was to comparatively examine the CA value in patients who underwent primary THA using the image-free navigation system either with a cup-first or stem-first technique.

Methods: Eighty-three hips undergoing primary THA using the OrthoPilot® image-free navigation system (B.

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Background: Major vascular injury is one of the most devastating complications in total hip arthroplasty (THA). Risk for intraoperative vascular injury is increased when the normal vascular anatomy is distorted by previous surgery or dislocation with displacement. Therefore, an appreciation of the vascular anatomy in relation to the anticipated surgical field is critical to avoid this complication during preoperative assessment for a complicated THA.

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The transverse acetabulum ligament (TAL) has been used as an intraoperative anatomical landmark to position the acetabulum cup in total hip arthroplasty (THA). However, the validity of the use of TAL has not been clarified. The purpose of this study was to examine the orientation of the cup component aligned with the TAL in cadaveric study.

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In total hip arthroplasty (THA), combined anteversion (CA), the sum of cup anteversion (AV) and stem antetorsion (AT) are used as parameters to assess the appropriateness of overall prosthetic alignment. In this study, we evaluated the CA value based on the post-operative computed tomography (CT) measurements in our patient population who underwent THA using the OrthoPilot™ image-free navigation system (B/BRAUN-Aesculap, Tuttlingen, Germany). During surgery, cup alignment was adjusted with the use of the navigation system while the positioning of the femoral stem was arbitrarily adjusted by the surgeon.

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Although rarely encountered, major vascular injury is a serious complication of total hip arthroplasty (THA). We report the case of an 85-year-old woman who sustained a deep femoral artery injury associated with a superficial femoral artery thrombosis during revision of a dislocated bipolar hemiarthroplasty to a THA. Altered anatomy due to migration of the femoral head was thought to be one of the factors leading to this complication.

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Various types of hip lesion associated with long-term haemodialysis have been observed. We present a new radiological classification system of haemodialysis-related hip arthropathy. In total, 103 hip lesions were analyzed in 84 patients undergoing haemodialysis for more than ten years.

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