Purpose The posterior approach is widely used in femoral hemiarthroplasty. The major problem with this approach is the high risk of postoperative dislocation. A modified posterior approach, the conjoined tendon preserving posterior approach (CPP), was developed to reduce postoperative dislocations. The objective of this multicenter study was to evaluate the efficacy and safety of hemiarthroplasty performed using the CPP approach for femoral neck fractures. Methods A total of 322 patients with femoral neck fracture, from 10 facilities, were prospectively studied. Bipolar hemiarthroplasty using the CPP approach was performed, using the same type of implants. Hip joint movement was not restricted following surgery, regardless of a patient’s cognitive status. Final follow-up was performed 9.1 ± 1.5 months after surgery. Results Hemiarthroplasty was undertaken in 320 patients using the CPP approach. The mean age, operative time, and intraoperative blood loss were 83.3 ± 7.4 years, 70.0 ± 22.7 min, and 134.8 ± 107.9 mL, respectively. No postoperative dislocations were observed during the study period. Intraoperative adverse events related to the hip joint included femoral fractures in five patients (1.6%) and trochanteric fractures in four patients (1.3%). Postoperative hip joint adverse events included a periprosthetic fracture in one patient (0.3%), deep infection in two patients (0.6%), and stem subsidence in one patient (0.3%). Postoperative deaths occurred in 23 patients (7.2%). One patient (0.3%) had a severe non-hip adverse event unrelated to surgery that prevented independent living, while five patients (1.6%) had a moderate non-hip adverse event that required treatment. Conclusion The CPP approach prevented postoperative dislocation following femoral hemiarthroplasty in elderly patients, with no CPP-associated specific adverse events.

We evaluated the clinical and radiographic outcomes of femoral head penetration and total hip arthroplasties with untreated and poly (2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted highly cross-linked polyethylene (HXLPE) acetabular liners against 26-, 28-, and 32-mm cobalt–chromium alloy femoral heads 3 years after the index surgery. Three combinations of the articulating surfaces were evaluated in the present study: untreated or PMPC-grafted HXLPE liner against 26- or 28-mm femoral heads (n = 16, 24) [control (26 or 28 mm) and PMPC (26 or 28 mm)] and PMPC-grafted HXLPE liner against 32-mm femoral heads (n = 64) [PMPC (32 mm)]. The clinical outcomes improved at 3 years postoperatively for the groups. No periprosthetic osteolysis or acetabular component migration was detected, and no revision surgery was performed among the groups. The steady-state wear rate of the PMPC (26 or 28 mm) group (0.021 mm/year) was lower than that of the control (26 or 28 mm) group (− 0.015 mm/year); the steady-state wear was under the clinical threshold. In contrast, the steady-state wear rate of the PMPC (32 mm) group (-0.006 mm/year) showed no significant difference when compared to that of the PMPC (26 or 28 mm) group (p < 0.01). The results obtained in the present study clearly demonstrate that PMPC-grafting onto an HXLPE surface improved the wear resistance of acetabular liners, even when coupled with larger femoral heads. Although further follow-up evaluations are required, PMPC-grafted HXLPE acetabular liners may be a promising approach to extend the longevity of artificial joints.

No abstract

No abstract