PurposeThe difficulty of femoral preparation with supine-position hip hemi-arthroplasty (HA) often leads to intra-operative fractures (IOFs). We aimed to clarify the incidence and types of IOFs in HA for hip fractures performed in the supine and lateral positions.Materials and MethodsWe retrospectively investigated cases of HA for acute femoral neck fractures from June 2013 to May 2018. We examined the incidence and types of IOFs according to different approaches. We defined supine-position in HA as the supine and hip-hyperextended (over-range) femoral preparation position, and lateral position as the lateral and hip-flexed femoral preparation position. We used a short tapered wedged stem.ResultsSupine-position HA was used in 46 patients (23.7%) and lateral-position HA in 148 patients (76.3%). IOFs in supine-position HA occurred in 8 patients (17.4%) and included five Vancouver AGT and three Vancouver B2 fractures. IOFs in lateral-position HA occurred in 3 patients (2.0%) and included one Vancouver AGT and two Vancouver B fractures. Supine-position HA was a risk factor for IOFs (adjusted odds ratio, 9.71; 95% confidence interval, 2.37–39.8; P<0.01)ConclusionSupine-position in HA is an IOF risk factor and significantly increases the incidence of great trochanter fractures of Vancouver type A.

The optimal placement within 3 degrees in coronal alignment was reportedly achieved in only 60 to 80% of patients when using an extramedullary alignment guide for the tibial side in total knee arthroplasty (TKA). This probably occurs because the extramedullary alignment guide is easily affected by the position of the ankle joint which is difficult to define by tibial torsion. Rotational direction of distal end of the extramedullary guide should be aligned to the anteroposterior (AP) axis of the proximal tibia to acquire optimal coronal alignment in the computer simulation studies; however, its efficacy has not been proven in a clinical setting. The distal end of the guide can be overly displaced from the ideal position when using a conventional guide system despite the alignment of the AP axis to the proximal tibia. This study investigated the effect of displacement of the distal end of extramedullary guide relative to the tibial coronal alignment while adjusting the rotational alignment of the distal end to the AP axis of the proximal tibia in TKA. A total of 50 TKAs performed in 50 varus osteoarthritic knees using an image-free navigation system were included in this study. The rotational alignment of the proximal side of the guide was adjusted to the AP axis of the proximal tibia. The position of the distal end of the guide was aligned to the center of the ankle joint as viewed from the proximal AP axis (ideal position) and as determined by the navigation system. The tibial intraoperative coronal alignments were recorded as the distal end was moved from the ideal position at 3-mm intervals. The intraoperative alignments were 0.5, 0.9, and 1.4 degrees in valgus alignment with 3-, 6-, and 9-mm medial displacements, respectively. The intraoperative alignments were 0.7, 1.2, and 1.7 degrees in varus alignment with 3-, 6-, and 9-mm lateral displacements, respectively. In conclusion, the acceptable tibial coronal alignment (within 2 degrees from the optimal alignment) can be achieved, although some displacement of the distal end from the ideal position can occur after the rotational alignment of the distal end of the guide is adjusted to the AP axis of the proximal tibia.

Late segmental collapse after internal fixation for femoral neck fracture is the phenomenon observed in post-traumatic osteonecrosis of the femoral head (ON), which has generally been reported to occur over a year or more after internal fixation. Subchondral insufficiency fracture of the femoral head (SIF) has also been recognized to cause femoral head collapse, however, only two cases of SIF after internal fixation for femoral neck fracture have been reported. We report a case with femoral head collapse observed 5 months after internal fixation for femoral neck fracture, which was histopathologically diagnosed as SIF. Clinically, differentiating SIF from ON is important because some cases of SIF have been reported to heal without surgical treatments. The timing of femoral head collapse after femoral neck fracture may be different between SIF and post-traumatic ON.

In this present study, four hemodialyzed patients with cervical myelopathy treated by canal-expansive laminoplasty are reported. The average duration of hemodialysis was 18 years, and the average follow-up was 16 months. Early results show maintenance of sagittal alignment and reduction of instability of the cervical spine with no progression of the destructive spondyloarthritis.

No abstract