Springer Science and Business Media LLC

Background. Dislocation after total hip arthroplasty (THA) is one of the most common major complications, and occurs more often through a posterior approach. We performed a retrospective study to determine the incidence of early dislocation and the relationship to the type of prosthesis and the surgeon's experience. Methods. A group of 884 consecutive primary THAs (746 cemented and 138 cementless) approached through a posterior incision with repair of the posterior soft tissues was followed for a mean of 30 months. Results. The overall dislocation rate was 1.36% (cemented: 1.1%; cementless: 2.9%). All dislocations were posterior and occurred within 6 months after surgery, 91% within 6 weeks. Dislocations were most common in rheumatoid patients (3.8%). Two revisions (0.23%) of the acetabular cup were performed for recurrent dislocations. The dislocation rate was not higher in the operations performed by less experienced surgeons. Conclusion. The early dislocation rate after primary THA through a posterior approach with repair of the posterior soft tissues was low, especially in cemented THA. Less experienced surgeons were not associated with a higher dislocation rate.

Insertion of iliac wing implants requires understanding of the curvilinear shape of the ilium. This study serves to quantitatively identify the area of iliac inner-outer table convergence (IOTC), characterize the iliac wing osseous corridor, and define the gluteal pillar osseous corridor. Computed tomography scans of 100 male and 100 female hemipelves were evaluated. The iliac wing was studied using manual best-fit analysis of the bounds of the inner and outer cortices. The IOTC was defined as the location of the iliac wing with an intercortical width less than 5 mm. The shortest distance from the apex of the iliac crest to the superior border of the IOTC was defined as the iliac wing osseous corridor. Finally, the width of the gluteal pillar corridor from the gluteus medius tubercle to the ischial tuberosity was measured. The IOTC is an elliptical area measuring 22.3 cm2. All ilia had an area where the inner and outer cortices converged to an intercortical width of less than 5 mm; 48% converged to a single cortex. The shortest mean distance from the superior edge of the iliac crest to the beginning of the IOTC was 20.3 mm in men and 13.8 mm in women (p < 0.001). The gluteal pillar diameter averaged 5.3 mm in men and 4.3 mm in women (p < 0.001). All ilia converge to a thin and frequently unicortical central region. A 4.5 mm iliac wing lag screw will not breach the cortex if it remains within 20 mm or 14 mm distal to the cranial aspect of the iliac crest in males and females, respectively. Not only is the gluteal pillar smaller than previously thought, in 41% of males and 73% of females, it is not be large enough for 5 mm implants. This study quantitatively assesses the dimensions of the IOTC, the iliac crest osseous corridor, and the gluteal pillar. Overall, our findings provide improved understanding of the limits for implant use in the iliac wing as well as better appreciation of the complex osteology of the ilium. This will help surgeons to identify safe areas for implant placement and avoid inadvertent cortical penetration.

Twenty patients, 17 to 87 years of age, were treated with a dynamic brace for fractures of the humerus. The brace acts by compressing the soft tissues surrounding the fractured bone while the dependent arm of the ambulatory patient helps to pull the displaced bone fragments into normal relationship. As soon as the initial swelling and pain subsides the brace can be applied, usually within the first week. The brace permits early exercise of all the joints; it gives good comfort to the patient. There were two nonunions. Eighteen fractures healed with good anatomical and functional outcome.