BACKGROUND: Along with the advances in technology of three-dimensional (3D) printer, it became a possible to make more precise patient-specific 3D model in the various fields including oral and maxillofacial surgery. When creating 3D models of the mandible and maxilla, it is easier to make a single unit with a fused temporomandibular joint, though this results in poor operability of the model. However, while models created with a separate mandible and maxilla have operability, it can be difficult to fully restore the position of the condylar after simulation. The purpose of this study is to introduce and asses the novel condylar repositioning method in 3D model preoperational simulation. METHODS: Our novel condylar repositioning method is simple to apply two irregularities in 3D models. Three oral surgeons measured and evaluated one linear distance and two angles in 3D models. RESULTS: This study included two patients who underwent sagittal split ramus osteotomy (SSRO) and two benign tumor patients who underwent segmental mandibulectomy and immediate reconstruction. For each SSRO case, the mandibular condyles were designed to be convex and the glenoid cavities were designed to be concave. For the benign tumor cases, the margins on the resection side, including the joint portions, were designed to be convex, and the resection margin was designed to be concave. The distance from the mandibular ramus to the tip of the maxillary canine, the angle created by joining the inferior edge of the orbit to the tip of the maxillary canine and the ramus, the angle created by the lines from the base of the mentum to the endpoint of the condyle, and the angle between the most lateral point of the condyle and the most medial point of the condyle were measured before and after simulations. Near-complete matches were observed for all items measured before and after model simulations of surgery in all jaw deformity and reconstruction cases. CONCLUSIONS: We demonstrated that 3D models manufactured using our method can be applied to simulations and fully restore the position of the condyle without the need for special devices.
Chin ; Congenital Abnormalities ; Equidae ; Glenoid Cavity ; Humans ; Jaw ; Joints ; Mandible ; Mandibular Condyle ; Mandibular Osteotomy ; Maxilla ; Methods ; Oral and Maxillofacial Surgeons ; Orbit ; Orthognathic Surgery ; Osteotomy, Sagittal Split Ramus ; Surgery, Oral ; Temporomandibular Joint

BACKGROUND: Reverse total shoulder arthroplasty has become a widely accepted surgical procedure in Japan since the time when the implants were approved for use in 2014. There is a doubt, however, as to whether the implants designed for Western people are suitable for Japanese people, particularly for females of relatively small stature. The purpose of this study was to investigate the glenoid dimension, with special focus on the length after glenoid reaming, in Japanese rotator cuff tear patients. METHODS: Fifty-six shoulders of 55 patients (35 males and 20 females; mean age, 63.8 years) were studied. Using the three-dimensional computed tomography images of the entire scapula before shoulder surgery, we measured the glenoid height and width, and calculated the correlation between these measurements and the patient's height. Further, we measured the anteroposterior length of the scapular neck at the subchondral bone and the length at 15 mm medial to the subchondral bone, to simulate both the glenoid width after reaming (width of the ‘virtual reamed surface’) and the space available for the end of the center post of a standard glenoid baseplate. RESULTS: The average glenoid height and width were 35.8 mm and 28.1 mm in males and 30.8 mm and 23.4 mm in females, respectively. There was a significant correlation between patient height and glenoid size (glenoid height, r = 0.69; width, r = 0.75; p < 0.01). The mean value of the width of the virtual reamed surface was 27.0 mm in males and 22.5 mm in females. The mean anteroposterior length at 15 mm medial to the subchondral bone was 12.4 mm in males and 9.5 mm in females; the length was shorter than 8 mm in 6 female shoulders. CONCLUSIONS: There was a significant correlation between patient height and glenoid size. Considering that the common diameter of the commercially available baseplates and their center posts is greater than 25 mm and 8 mm, respectively, these prosthetic parts would be too large, especially for the Japanese female glenoid. Given that the current results of Japanese shoulder dimensions are similar to those of Asian people, ‘Asian size implants’ should be developed.
Arthroplasty ; Asian Continental Ancestry Group* ; Female ; Glenoid Cavity ; Humans ; Japan ; Male ; Neck ; Rotator Cuff* ; Scapula* ; Shoulder ; Tears*

BACKGROUND: To evaluate the clinical and functional outcomes of arthroscopic-assisted reduction and percutaneous screw fixation for glenoid fractures with scapular extension, and investigate the radiologic and clinical benefits from the results. METHODS: We evaluated patients treated with arthroscopic-assisted reduction and percutaneous screw fixation for glenoid fractures with scapular extension from November 2008 to September 2015. Fractures with displacement exceeding one-fourth of the anterior-articular surface or more than one-third of the posterior-articular surface in radiographic images were treated by surgery. Clinical assessment was conducted based on range of motion, Rowe score, and Constant score of injured arm and uninjured arm at last follow-up. RESULTS: Fifteen patients with Ideberg classification grade III, IV, and V glenoid fracture who underwent arthroscopic-assisted reduction using percutaneous screw fixation were retrospectively enrolled. There were no differences in clinical outcomes at final follow-up compared to uninjured arm. Bone union was seen in all cases within five months, and the average time to bone union was 15.2 weeks. Ankylosis in one case was observed as a postoperative complication, but the symptoms improved in response to physical therapy for six months. There was no failure of fixation and neurovascular complication. CONCLUSIONS: We identified acceptable results upon radiological and clinical assessment for the arthroscopic-assisted reduction and percutaneous fixation. For this reason, we believe the method is favorable for the treatment of Ideberg type III, IV, and V glenoid fractures. Restoration of the articular surface is considered to be more important than reduction of fractures reduction of the scapula body.
Ankylosis ; Arm ; Arthroscopy ; Classification ; Follow-Up Studies ; Fracture Fixation ; Glenoid Cavity ; Humans ; Methods ; Postoperative Complications ; Range of Motion, Articular ; Retrospective Studies ; Scapula

Synovial chondromatosis is a rare benign lesion originating from the synovial membrane. It presents as adhesive or non-adhesive intra-articular cartilaginous loose bodies. Although the causes of synovial chondromatosis have not been fully elucidated, inflammation, external injury, or excessive use of joints have been suggested as possible causes. Synovial chondromatosis has been reported to occur most frequently at large joints that bear weights, with a rare occurrence at the temporomandibular joint (TMJ). When synovial chondromatosis develops at TMJ, clinical symptoms, including pain, joint sounds, and mouth opening may common. Moreover, synovial chondromatosis rarely spreads to the mandibular condyle, glenoid cavity, or articular eminence of TMJ. The goal of this study was to discuss the methods of surgery and other possible considerations by reviewing cases of patients who underwent surgery for synovial chondromatosis that extended to the temporal bone.
Adhesives ; Arthralgia ; Chondromatosis, Synovial* ; Glenoid Cavity ; Humans ; Inflammation ; Joints ; Mandibular Condyle ; Mouth ; Synovial Membrane ; Temporal Bone* ; Temporomandibular Joint* ; Weights and Measures

Synovial chondromatosis is a rare benign lesion originating from the synovial membrane. It presents as adhesive or non-adhesive intra-articular cartilaginous loose bodies. Although the causes of synovial chondromatosis have not been fully elucidated, inflammation, external injury, or excessive use of joints have been suggested as possible causes. Synovial chondromatosis has been reported to occur most frequently at large joints that bear weights, with a rare occurrence at the temporomandibular joint (TMJ). When synovial chondromatosis develops at TMJ, clinical symptoms, including pain, joint sounds, and mouth opening may common. Moreover, synovial chondromatosis rarely spreads to the mandibular condyle, glenoid cavity, or articular eminence of TMJ. The goal of this study was to discuss the methods of surgery and other possible considerations by reviewing cases of patients who underwent surgery for synovial chondromatosis that extended to the temporal bone.
Adhesives ; Arthralgia ; Chondromatosis, Synovial* ; Glenoid Cavity ; Humans ; Inflammation ; Joints ; Mandibular Condyle ; Mouth ; Synovial Membrane ; Temporal Bone* ; Temporomandibular Joint* ; Weights and Measures

We, herein, present a patient with no history of trauma who developed shoulder pain after undergoing low-voltage electric shock. According to the computed tomography, there was a multi-segmental fracture that extended into the glenoid cavity of the left scapula. A good outcome was obtained after open reduction and internal fixation. Emergency physicians should be aware of the possibility of scapular fracture extending into the glenoid cavity, especially in patients with shoulder pain after electrical injury.
Electric Injuries ; Emergencies ; Glenoid Cavity* ; Humans ; Scapula ; Shock* ; Shoulder Pain

BACKGROUND: To evaluate the clinical and functional outcomes of arthroscopic-assisted reduction and percutaneous screw fixation for glenoid fractures with scapular extension, and investigate the radiologic and clinical benefits from the results. METHODS: We evaluated patients treated with arthroscopic-assisted reduction and percutaneous screw fixation for glenoid fractures with scapular extension from November 2008 to September 2015. Fractures with displacement exceeding one-fourth of the anterior-articular surface or more than one-third of the posterior-articular surface in radiographic images were treated by surgery. Clinical assessment was conducted based on range of motion, Rowe score, and Constant score of injured arm and uninjured arm at last follow-up. RESULTS: Fifteen patients with Ideberg classification grade III, IV, and V glenoid fracture who underwent arthroscopic-assisted reduction using percutaneous screw fixation were retrospectively enrolled. There were no differences in clinical outcomes at final follow-up compared to uninjured arm. Bone union was seen in all cases within five months, and the average time to bone union was 15.2 weeks. Ankylosis in one case was observed as a postoperative complication, but the symptoms improved in response to physical therapy for six months. There was no failure of fixation and neurovascular complication. CONCLUSIONS: We identified acceptable results upon radiological and clinical assessment for the arthroscopic-assisted reduction and percutaneous fixation. For this reason, we believe the method is favorable for the treatment of Ideberg type III, IV, and V glenoid fractures. Restoration of the articular surface is considered to be more important than reduction of fractures reduction of the scapula body.
Ankylosis ; Arm ; Arthroscopy ; Classification ; Follow-Up Studies ; Fracture Fixation ; Glenoid Cavity ; Humans ; Methods ; Postoperative Complications ; Range of Motion, Articular ; Retrospective Studies ; Scapula

Arthroscopy is recognized as an important adjunct in treatment of intra-articular fractures. The author reports on successful treatment of a displaced transverse glenoid cavity fracture, reduced and fixed with arthroscopic assist, using two cannulated screws perpendicular to the fracture surface, in a patient with frail chest. One screw passed through the Neviaser portal, and the other screw passed through the base of the coracoid process. Arthroscopy assisted reduction and 2 cannulated screw fixation through the Neviaser portal and coracoid base appears to be a good method for treatment of transverse glenoid fractures.
Arthroscopy* ; Glenoid Cavity ; Humans ; Intra-Articular Fractures ; Methods ; Thorax

Arthroscopy is recognized as an important adjunct in treatment of intra-articular fractures. The author reports on successful treatment of a displaced transverse glenoid cavity fracture, reduced and fixed with arthroscopic assist, using two cannulated screws perpendicular to the fracture surface, in a patient with frail chest. One screw passed through the Neviaser portal, and the other screw passed through the base of the coracoid process. Arthroscopy assisted reduction and 2 cannulated screw fixation through the Neviaser portal and coracoid base appears to be a good method for treatment of transverse glenoid fractures.
Arthroscopy ; Glenoid Cavity ; Humans ; Intra-Articular Fractures ; Methods ; Thorax

Shoulder surgeons need to be aware of the critical size of the glenoid or humeral osseous defects seen in patients with anterior shoulder instability, since the considerable size of osseous defect is reported to cause postoperative instability. Biomechanical studies have identified the size of the osseous defect which affects stability. Since engagement always occurs between a Hill-Sachs lesion and the glenoid rim, when considering the critical size of the Hill-Sachs lesion, we have to simultaneously consider the size of the glenoid osseous defect. With the newly developed concept of the glenoid track, we are able to evaluate whether a large Hill-Sachs lesion is an "on-track" or "off-track" lesion, and to consider both osseous defects together. In case of an off-track Hill-Sachs lesion, if the glenoid defect is less than 25%, no treatment is required. In this case, the Latarjet procedure or arthroscopic remplissage procedure can be a treatment option. However, if the glenoid defect is more than 25%, treatment such as bone grafting is required. This will convert an off-track lesion to an on-track lesion. After the bone graft or Latarjet procedure, if the Hill-Sachs lesion persists as off-track, then further treatment is necessitated. In case with an on-track Hill-Sachs lesion and a less than 25% glenoid defect, arthroscopic Bankart repair alone is enough.
Biomechanical Phenomena ; *Glenoid Cavity/injuries/pathology/physiopathology ; Humans ; *Humeral Head/injuries/pathology/physiopathology ; Shoulder Dislocation/physiopathology ; *Shoulder Joint/injuries/pathology/physiopathology