AimsConcurrent hip and spine pathologies can alter the biomechanics of spinopelvic mobility in primary total hip arthroplasty (THA). This study examines how differences in pelvic orientation of patients with spine fusions can increase the risk of dislocation risk after THA.Patients and MethodsWe identified 84 patients (97 THAs) between 1998 and 2015 who had undergone spinal fusion prior to primary THA. Patients were stratified into three groups depending on the length of lumbar fusion and whether or not the sacrum was involved. Mean age was 71 years (40 to 87) and 54 patients (56%) were female. The mean body mass index (BMI) was 30 kg/m2(19 to 45). Mean follow-up was six years (2 to 17). Patients were 1:2 matched to patients with primary THAs without spine fusion. Hazard ratios (HR) were calculated.ResultsDislocation in the fusion group was 5.2% at one year versus 1.7% in controls but this did not reach statistical significance (HR 1.9; p = 0.33). Compared with controls, there was no significant difference in rate of dislocation in patients without a sacral fusion. When the sacrum was involved, the rate of dislocation was significantly higher than in controls (HR 4.5; p = 0.03), with a trend to more dislocations in longer lumbosacral fusions. Patient demographics and surgical characteristics of THA (i.e. surgical approach and femoral head diameter) did not significantly impact risk of dislocation (p > 0.05). Significant radiological differences were measured in mean anterior pelvic tilt between the one-level lumbar fusion group (22°), the multiple-level fusion group (27°), and the sacral fusion group (32°; p < 0.01). Ten-year survival was 93% in the fusion group and 95% in controls (HR 1.2; p = 0.8).ConclusionLumbosacral spinal fusions prior to THA increase the risk of dislocation within the first six months. Fusions involving the sacrum with multiple levels of lumbar involvement notably increased the risk of postoperative dislocation compared with a control group and other lumbar fusions. Surgeons should take care with component positioning and may consider higher stability implants in this high-risk cohort.

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At the 1-year postoperative follow-up, incorporation and ligamentization of the STG and ST4 grafts were the same based on MRI analysis. The results were at least as good with the ST4 technique as with the standard STG technique in terms of incorporation and ligamentization.

This meta-analysis found no evidence that using patient-specific cutting blocks provides superior accuracy to using manual instrumentation during TKA.

The significance of weight in the indications for unicompartmental knee replacement (UKR) is unclear. Our hypothesis was that weight does not affect the long-term rate of survival of UKRs. We undertook a retrospective study of 212 UKRs at a mean follow-up of 12 years (7 to 22). The patients were distributed according to body mass index (BMI; < vs ≥ 30 kg/m(2)) and weight (< vs ≥ 82 kg). Kaplan-Meier survivorship analysis was performed and ten-year survival rates were compared between the sub-groups. Multimodal regression analysis determined the impact of the various theoretical contraindications on the long-term rate of survival of UKR. The ten-year rates of survival were similar in the two weight subgroups (≥ 82 kg: 93.5% (95% confidence interval (CI) 66.5 to 96.3); < 82 kg: 92.5% (95% CI 82.5 to 94.1)) and also in the two BMI subgroups (≥ 30 kg/m(2): 92% (95% CI 82.5 to 95.3); < 30 kg/m(2): 94% (95% CI 78.4 to 95.9)). Multimodal regression analysis revealed that weight plays a part in reducing the risk of revision with a relative risk of 0.387, although this did not reach statistical significance (p = 0.662). The results relating weight and BMI to the clinical outcome were not statistically significant. Thus, this study confirms that weight does not influence the long-term rate of survival of UKR.

This review describes bone and nerve injury mechanisms during a femoral head fracture-dislocation and outlines a novel classification system that uses computed tomography scanning (CT scan) to help determine how to best treat these fractures in an emergency setting or in chronic cases. A series of 55 cases with CT scan performed in the emergency department (ED) and an average follow-up of 9 years (range 3-13) was used as a basis to develop the classification system; this system takes into account the size of the fragments and any associated acetabular wall or femoral neck fractures. The suggested course of action is based on the CT scan results after the hip joint is reduced. Conservative treatment is indicated every time the head fragments and any potential acetabular wall fragments are properly reduced and there are no foreign bodies (37.7%). Osteochondral head fragments below the fovea must be removed (36.3%). Fragments that are one-third or one-quarter of the head size can either be removed (7.2%) or reduced and fixed (5.4%). A novel medial approach is described that provides minimally invasive access to the anterior-inferior part of the femoral head, which should extend the indications for preservation of one-third head fragments. If the femoral neck is also fractured or a one-half head fragment exists in elderly patients, a total hip replacement should be considered right way (9%). At the latest follow-up, osteoarthritis was present in 43.7% of cases, but was mostly well tolerated - 94% of patients had a WOMAC score between 80 and 100 with signs of osteoarthritis visible on radiographs. Paradoxically, avascular necrosis (9%) is due to small head fractures. The results of our series are compared with the few series that have been published since CT scanning has been systematically used in the ED.

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