Materials and Methods: Forty eight hips with the conversion of bipolar HA to THA were followed up for an average 6.2 years (range 2.0-11.5 years). Twenty one hips had conversion surgery to THA using metal-on-metal articulation (28 or 32 mm head). Nine hips used ceramic-on-ceramic (28-40 mm) and eighteen hips used large head metal-on-metal bearing (>40 mm). Outcome was evaluated using Harris Hip Score (HHS) and Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) score. The radiographs were analyzed for evidence of osteolysis and/or loosening. The complications were evaluated, especially dislocation with different femoral head diameter.
Results: Average HHS significantly improved from 42 preoperatively to 86 postoperatively and the average WOMAC score also significantly improved from 47 to 22 postoperatively. Radiological evaluation showed all the femoral components were stable. There was one acetabular component loosening, which required revision 9 years after conversion to THA. One dislocation and one recurrent dislocation were recorded in isolated acetabular revision hip; whereas one dislocation, one recurrent dislocation, and one trochanteric nonunion occurred in the hips with revision of both components. All dislocations occurred in hips with a femoral head size of 28 mm (P = 0.052). The cup and femoral head interval length was the most significant factor contributing to dislocation (P = 0.013).
Conclusions: Conversion THA after failed bipolar HA offers a reliable pain relief and functional improvement. To prevent dislocation, it is highly recommended to use a larger diameter femoral head, especially where the cup size is big.
Materials and Methods: We reviewed prospectively collected data in our tertiary hospital arthroplasty registry and identified patients who underwent revision THA between 2001 and 2014, with a minimum of two years follow-up. The study group (two-stage revision THA for PJI) consists of 23 patients and the control group (one-stage revision THA for aseptic reasons) consists of 231 patients. Patient demographics, Western Ontario and McMaster Universities Arthritis Index (WOMAC), Oxford Hip Score (OHS), Short Form-36 (SF-36) scores and patient reported satisfaction were evaluated. Student's t-test was used to compare continuous variables between the two groups. Statistical significance was defined as p <0.05.
Results: The pre-operative demographics and clinical scores were relatively similar between the two groups of patients. At two years, patients who underwent revision THA for PJI reported a better WOMAC Pain Score and OHS as compared to aseptic revision THA. A similar proportion of patients were satisfied with their results of surgery in both groups (p=0.093).
Conclusions: Although patients who underwent revision THA for PJI had poorer pre-operative functional scores (WOMAC function and SF-36 PF), at two years follow-up, these two groups of patients have comparable post-operative outcomes. Interestingly, patients who had revision THA for PJI reported a better clinical outcome in terms of OHS and WOMAC Pain score as compared to the aseptic group. We conclude that the revision THA for PJI is not inferior to aseptic revision THA in terms of patient satisfaction and clinical outcomes.
Materials and Methods: This is a single-center quasi-experimental study involving 100 patients seen in the outpatient department with knee osteoarthritis. They were randomly (computer generated) allocated into two arms (high frequency [H-F] or low frequency [L-F]). H-F is set at 100 Hz and L-F is set at 4 Hz. A baseline assessment is taken with the visual analog score (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Oxford Knee Score, and Lequesne index. They were instructed to self-administer the TENS therapy as per protocol and followed up at the 4th and 12th week to be reevaluated on the above scores.
Results: The final results show that both H-F and L-F groups showed improvement in all parameters of the VAS, WOMAC index, Oxford Knee Score, and Lequesne index (73%). Only the pain component of Lequesne index, activities of daily living component of Lequesne index, total Lequesne index, and pain component of WOMAC index shows a statistically significant difference, favoring the H-F group. The H-F group yields a faster result; however, with time the overall effect remains the same in both groups.
Conclusion: Both H-F and L-F groups show improvement in all the component of Lequesne index, Oxford Knee Score, WOMAC index, and VAS with no statistical difference between the two groups. Although H-F yields a faster result, not everyone is able to tolerate the intensity. Therefore, the selection of H-F or L-F should be done on case basis depending on the severity of symptoms, patient's expectation, and patient's ability to withstand the treatment therapy. Based on this 12th week follow-up, both groups will continue to improve with time. A longer study should be conducted to see it this improvement will eventually plateau off or continue to improve until the patient is symptom free.