Unsintered hydroxyapatite (u-HA) and poly-L-lactide (PLLA) composites (u-HA/PLLA) are osteoconductive and biodegradable. Screw (Super-Fixsorb MX30) and plate (Super-Fixsorb MX40 Mesh) systems made of u-HA/PLLA are typically used in small bones in maxillofacial surgeries. After the resection of bone tumors in larger bones, reconstructions with β-tricalcium phosphate (β-TCP) implants of strong compression resistance have been reported. After a resection, when the cavity is hemispheric- or concave-shaped, stabilization of the implanted β-TCP block is necessary. In the current series, u-HA/PLLA were used to stabilize the mechanically strong implanted low-porous β-TCP blocks in six bone tumor cases, including three giant cell tumors of bone, and one case each of chondroblastoma, chondrosarcoma, and parosteal osteosarcoma. The mean age of patients at the time of surgery was 31.3 years (range, 19 to 48 years). The bones involved were two ilia (posterior), a femur (diaphysis to distal metaphysis), and three tibias (proximal epiphysis, proximal metaphysis to epiphysis, and distal metaphysis to epiphysis). Neither displacement of the implanted β-TCP block nor any u-HA/PLLA-related complications were observed. The radiolucent character of the u-HA/PLLA did not hinder radiological examinations for potential signs of tumor recurrence. The method of using u-HA/PLLA components for the stabilization of β-TCP blocks makes the procedure easy to perform and reliable. It can extend the application of β-TCP blocks in reconstruction surgery.
Bone Neoplasms ; Chondroblastoma ; Chondrosarcoma ; Durapatite* ; Epiphyses ; Femur ; Giant Cell Tumors ; Humans ; Hydroxyapatites ; Methods ; Osteosarcoma ; Reconstructive Surgical Procedures ; Recurrence ; Tibia

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*

Methods: Cancellous bone was collected from the anterior iliac crest during lateral interbody fusion (LIF), and the bone void of the ilium was refilled with a porous HAp/Col composite. We assessed bone recovery using computed tomography (CT). From the 74 patients who underwent LIF between January 2015 and December 2016, we included 49 patients whose iliac crest could be evaluated using CT at 3 months and 1 year after the surgery. Results: Bone defects decreased in a time-dependent manner after the surgery. Cortical closure was observed in 28.5% of the cases 3 months after the surgery; at 1 year postoperatively, 95.9% of the patients had cortical closure. Complete repair of the cancellous bone was achieved in 57.1% of the patients at 3 months after the surgery and in 95.9% at 1 year after the surgery. There were no significant hematomas, infections, iliac crest fractures, or soft tissue herniation. Conclusions Radiographic recovery of cortical and cancellous bone defects was achieved with high probability via refilling with HAp/Col composite over the 1-year period.

The purpose of this study was to introduce our patient-specific bioactive porous titanium implant manufactured using selective laser melting (SLM) and to establish the efficacy and safety of the implant for stand-alone anterior cervical discectomy and fusion (ACDF) based on a prospective clinical trial. We designed a customized ACDF implant using patient-specific data and manufactured the implant using SLM. We produced a bioactive surface through a specific chemical and thermal treatment. Using this implant, we surgically treated four patients with cervical degenerative disc disease and evaluated the clinical and radiological results. We achieved successful bony union in all but one patient without autologous bone grafting within 1 year. We observed no implant subsidence during the follow-up period, and all clinical parameters improved significantly after surgery, with no reported implant-related adverse effects. Our customized bioactive porous titanium implant is a safe and promising implant for stand-alone ACDF.

Methods: For this prospective multicenter study, 40 patients were followed up through radiologic and clinical examinations for at least 1 year postoperatively. All surgical procedures were either single- or double-level LLIF using bioactive porous titanium spacers without bone grafts. Results: Four patients were excluded from the study owing to aggravation from other comorbidities. Another 36 patients, including 26 and 10 with single- and double-level LLIFs, respectively, participated in the follow-up. The mean age at the time of surgery was 63.7 years. The mean operating time was 50.5 minutes per level. The mean estimated intraoperative blood loss was 11.6 mL per level. Clinical scores improved in all cases and were maintained throughout the follow-up period. The intervertebral bony union rates were 67.4% and 84.8% at 6 and 12 months, respectively. Endplate cyst signs were observed in 13.0% and 8.7% of patients at 6 and 12 months, respectively. Fused segmental angles were maintained throughout the follow-up period, indicating no cage subsidence. Conclusions Single- and double-level LLIFs using bioactive porous titanium spacers without bone grafts were found to be minimally invasive, resulting in clinical and imaging results comparable with conventional procedures. Therefore, this type of implant may be an option for minimally invasive spinal fusion surgery.

The purpose of this study was to introduce our patient-specific bioactive porous titanium implant manufactured using selective laser melting (SLM) and to establish the efficacy and safety of the implant for stand-alone anterior cervical discectomy and fusion (ACDF) based on a prospective clinical trial. We designed a customized ACDF implant using patient-specific data and manufactured the implant using SLM. We produced a bioactive surface through a specific chemical and thermal treatment. Using this implant, we surgically treated four patients with cervical degenerative disc disease and evaluated the clinical and radiological results. We achieved successful bony union in all but one patient without autologous bone grafting within 1 year. We observed no implant subsidence during the follow-up period, and all clinical parameters improved significantly after surgery, with no reported implant-related adverse effects. Our customized bioactive porous titanium implant is a safe and promising implant for stand-alone ACDF.

STUDY DESIGN: Retrospective cohort study. PURPOSE: The aim of our study is to evaluate the extent of posterior spinal dural shift following spinous process splitting multi-level intervertebral lumbar laminectomies, and determine the relationship between posterior spinal dural shift and preoperative parameters. OVERVIEW OF LITERATURE: There are no existing studies on the posterior spinal dural shift after spinous process-splitting multi-leveled lumbar laminectomies. METHODS: We examined 37 patients who underwent spinous process-splitting laminectomies in at least two intervertebral levels, including at the L5/S level. We defined the distance between the vertebral bodies and the anterior edge of the dural sac in the magnetic resonance images at the L5 vertebral level as the anterior dural space (ADS) and detected the difference (d-ADS) between preoperative ADS (pre-ADS) and postoperative ADS (post-ADS). We assessed the relationship between ADS or d-ADS, and preoperative parameters, including age, sex, lumbar lordosis, focal lordosis (FL), and number of decompression levels. RESULTS: Post-ADS was significantly greater than pre-ADS (p<0.001). Pre-ADS was significantly correlated with FL (p=0.44, p<0.01) and also with post-ADS (p=0.43, p<0.01). d-ADS was negatively correlated with pre-ADS (p=−0.37, p<0.05). A single regression analysis revealed that the relationship between d-ADS and pre-ADS was described as d-ADS=3.67−0.46×pre-ADS. In one of three patients whose d-ADS was above the range of two standard errors, reoperation was performed because of impingement of the nerve root caused by the excessive posterior dural shift. CONCLUSIONS: Posterior dural shifts occur after spinous process-splitting multi-level lumbar laminectomies, including at the L5/S level. FL and pre-ADS are good predictive factors for posterior dural shift. Excessive posterior dural shift may lead to stretching and impingement of nerve roots and thus require attention.

Methods: This retrospective observational study included 42 patients who underwent reconstructive surgery for ASD. Elliptical regions of interest (ROIs) on the axial section and rectangular ROIs on the sagittal section were placed at the upper instrumented vertebrae (UIV), UIV+1, and UIV+2. In addition, the HU value of the L2 vertebra was used as the representative. Results: PJFr occurred in 28.6% of patients within 2 years following surgery. The HU values obtained from the axial sections of L2, UIV, UIV+1, and UIV+2 were not significantly associated with the incidence of PJFr within 2 years, except for the ROI set in the lower region of the L2 vertebra. However, the HU value of the anterior third of the UIV in the sagittal section was significantly lower in the PJFr group than in the nonPJFr group (87.0 vs. 160.3, p =0.001). A UIV HU value of <100 was associated with a higher incidence of PJFr than an HU vaue of >100 (p <0.05). Conclusions Measurements of HU in the anterior one-third of the UIV in the sagittal section demonstrated predictive ability for PJFr following ASD surgery. A UIV HU value of <100 emerged as a risk factor for PJFr.