CT scan analysis of implant mating comparing APA versus TEA in simultaneous bilateral TKA: One technique per knee.

BACKGROUND: The optimal landmark for setting femoral component rotation in primary TKA remains a debate. This study compares the Anterior-Posterior Axis (APA) versus the Transepicondylar Axis (TEA) in patients undergoing simultaneous bilateral TKA, where one reference line was randomized to each knee. Implant mating was assessed via post-operative CT scans. METHOD: The study included 32 patients with osteoarthritis in both knees with similar varus deformities. All patients underwent the same surgical procedure on both knees, aside from the selected femoral rotation axis line: APA randomized to one side and TEA to the contralateral. Post-operative CT scans were performed in extension to assess in-vivo mating. RESULTS: CT scan analysis showed mean rotation of the femoral implant externally rotated relative to the radiographic TEA with no significant difference between the APA and TEA groups (p = 0.28). Tibial implant rotation was also externally rotated to the radiographic TEA with no significant difference (p = 0.59). Femoral-tibial implant mating showed a mean external rotation of the tibia relative to the femur in both groups: 0.86 ± 4.0° external rotation in the APA group and 0.23 ± 3.7° external rotation in the TEA group. There was no significant difference between groups (p = 0.52). The range of mating mismatch was 15° in the APA group and 16.5° in the TEA group. CONCLUSIONS: When using a measured resection, posterior referencing technique, post-operative femoral-tibial implant mating measured by CT scan showed no superiority comparing the APA method versus the TEA method. LEVEL OF EVIDENCE: 2 Randomized prospective study.

Factors Affecting Life Expectancy After Bone Metastasis in Adults - Results of a 5-year Prospective Study.

There is a scarcity of literature available regarding the factors affecting life expectancy in bone metastasis (BM). Our objective is to evaluate the factors affecting life expectancy in adult patients with BM. In this prospective cohort study for over 5 years, 111 adults with BM were included in the analysis. The life expectancy was calculated from the time of diagnosis of BM to death. Statistical analysis was done using the SPSS statistical program. The Pearson chi-square test was used to analyze the significance and life expectancy was represented on the Kaplan Meier curve. The overall median survival time was 9 months. The patients with a primary malignancy detected along with BM had a median survival of 9 months. Those without a known primary at the time of diagnosis survived for a median period of 8 months and those with known primary for 14 months (P-value 0.01). The median survival of patients with BM from the lung, breast, and prostate was 6, 14, and 24 months, respectively (P-value 0.001). Only 22% of patients with extraskeletal metastasis in addition to BM survived more than 6 months (P-value 0.013). Patients with neurological deficits had a median survival of 2 months (P-value 0.0001). There was no statistically significant association between gender and the mode of treatment and survival. There was a significant association between life expectancy and mode of presentation, the primary site of origin, presence of extraskeletal secondary, BM with unknown primary, and symptoms on presentation in patients with BM.

Skeletal Metastasis-an Epidemiological Study.

Metastasis is the commonest bone tumors. The commonest primary metastasis to the bone are the breast, lung, prostate, kidney, and thyroid. The bone is the third common site of metastatic disease, only the lung and the liver have higher metastatic rate than skeleton. We have no epidemiological studies conducted to evaluate the various aspects of skeletal metastasis like age, sex distribution, presentation, common sites of primary and associated secondary metastases, and investigation from Indian subcontinent. Here we are presenting the first epidemiological study of skeletal metastasis from our region. We have conducted a prospective descriptive study in the Departments of Orthopedics and Radiotherapy, Government Medical College, Kozhikode, during the period of 2007 to 2009. One hundred eleven patients were included in the study above the age of 30 years. Clinical examination and investigation were done on these patients. Skeletal metastasis commonly occurs in the fifth decade of life with modest male preponderance. In most of the cases, the primary site of malignancy was undetected at the time of presentation. Pain was the commonest presented complaint of the patient. The spine is the commonest site affected and the lung was the common site of primary metastasis. Most of the cases were detected by radiogram and confirmation was obtained by minimally invasive technique like FNAC or CNB.