The effect of intramedullary bone plug on femoral stem migration of hydroxyapatite-coated hip arthroplasty

Limited influence of prosthetic position on aseptic loosening of elbow replacements: 125 elbows followed for an average period of 5.6 years

BACKGROUND

Aseptic loosening of elbow replacements, seen in long-term follow-up, remains a problem. In this study, we attempted to determine the influence of cementing technique, prosthetic position, different component sizes, use of a bone plug, and intraoperative fractures on the development and progression of radiolucent lines and aseptic loosening.

METHODS

We studied standard radiographs of 125 primary Souter-Strathclyde total elbow prostheses using the Wrightington method. Additionally, 104 preoperative radiographs were available for analysis. We used a Markow statistical model to detect relationships between all factors described above.

RESULTS

After a mean follow-up time of 5.5 (2-19) years, 21 (17%) prostheses had loosened radiographically (10-year survival: 65%). When the humeral component was tilted more medially or more anteriorly, we found development of radiolucent lines at the medial condyle and at the posterior side of the humeral component. However, the progression of these lines was not influenced by these positions. No other prognostic factors for radiolucent lines or aseptic loosening were found.

INTERPRETATION

Despite the small number of elbows studied, the weak influence of prosthetic position on aseptic loosening gives more ground for a multifactorial cause for aseptic loosening of the Souter-Strathclyde total elbow prosthesis.

The effect of intramedullary corticocancellous bone plug for hip hemiarthroplasty

BACKGROUND

A prospective review was performed on 60 consecutive patients with hip hemiarthroplasty after femoral neck fractures.

METHODS

Twenty-two patients underwent Austin Moore hemiarthroplasty with an intramedullary corticocancellous bone plug at the tip of the prosthesis (group A) and 38 patients underwent Austin Moore hemiarthroplasty alone (group B). The patients were evaluated clinically and radiographically at 3 and 6 months postoperatively and annually thereafter.

RESULTS

There was no statistically significant difference in thigh pain score between the two groups. At 3- and 6-month follow-up, 88% and 83% of group A patients experienced no pain or mild thigh pain, compared with 72% and 76% in group B, respectively. The radiographs revealed more stem subsidence and calcar osteolysis in group B than in group A (p < 0.01 and p < 0.05, respectively). Furthermore, in both groups there was a correlation between calcar atrophy, stem subsidence, and early clinical thigh pain score (p < 0.05).

CONCLUSION

Our data suggest that, whereas the radiologic findings in both groups may be related to thigh pain, they had little effect on the rate of femoral stem revision. We believe that the application of a corticocancellous bone plug in uncemented hip hemiarthroplasty for treatment of femoral neck fractures can decrease the incidence of early thigh pain in the first 6 months.