To date, several trials have reported the use of mesenchymal stem cell (MSC) implantation for osteonecrosis of the femoral head (ONFH). However, the clinical outcomes have not been conclusive. This study compared the clinical and radiological results of bone marrow mesenchymal stem cell (BMMSC) implantation with traditional simple core decompression (CD) using a matched pair case–control design. We retrospectively reviewed 100 patients with ONFH (106 hips) who had been treated by CD alone (50 patients, 53 hips) and CD + BMMSC implantation (50 patients, 53 hips) between February 2004 and October 2014. We assessed the total hip replacement arthroplasty (THA) conversion rate and ARCO (Association Research Circulation Osseous) stage progression. Survivor rate analysis was performed using the Kaplan–Meier method, and an additional THA was defined as the primary endpoints. The mean follow-up period was 4.28 years. There was a difference in the THA conversion rate between the CD (49%) and CD + BMMSC groups (28.3%) (p = 0.028). ARCO stage progression was noted in 20 of 53 hips (37.7%) in the CD group and 19 of 53 hips (35.8%) in the CD + BMMSC group. Among collapsed cases (ARCO stages III and IV), there was no difference in clinical failure rate between the two groups. Conversely, in the pre-collapse cases (ARCO stages I and II), only 6 of 30 hips (20%) progressed to clinical failure in the CD + BMMSC group, whereas 15 of 30 hips (50%) progressed to clinical failure in the CD group (p = 0.014). Kaplan–Meier survival analysis showed a significant difference in the time to failure between the two groups up to 10-year follow-up (log-rank test p = 0.031). There was no significant difference in terms of age (p = 0.87) and gender (p = 0.51) when comparing THA conversion rates between groups. No complication was noted. These results suggest that implantation of MSCs into the femoral head at an early stage of ONFH lowers the THA conversion rate. However, ARCO stage progression is not affected by this treatment. Retrospectively registered

Moon KH, et al. Hip Pelvis. 2014 Sep;26(3):129-135. http://dx.doi.org/10.5371/hp.2014.26.3.129

The aim of the present study was to evaluate the dislocation rate and the risk factors leading to instability after primary and revision total hip replacement arthroplasty (THRA) with constrained acetabular liners (CAL), as well as treatment strategies for prevention of dislocation. From 1999 to 2017, drawing on two institutions' THRA registries, we retrospectively identified 46 THRA cases using a CAL that had been followed up for a minimum of 4 years. The patients comprised 39 women and 7 men, with an average age of 69.1 years (age range, 41–98). Of the 46 patients, CAL were used in 12 patients for prevention of dislocation in primary THRA and in 34 patients for treatment of recurrent dislocation after primary THRA. Clinical and radiological evaluation were performed. We evaluated the failure rate of CAL as well as the risk factors. The 12 patients who used CAL for prevention of dislocation in primary THRA had no dislocation. However, 12 (35%) of the 34 hips had a dislocation after use of CAL in revision THRA. Patients with an abductor muscle weakness grade of ≤3 had a higher rate of dislocation than those with a grade of ≥4 (grade 1; likelihood ratio = ∞, grade 2; likelihood ratio = 1.83, grade 3; likelihood ratio = 1.05, grade 4; likelihood ratio = 0.46, and grade 5; likelihood ratio = 0). The group of primary THRA with CAL had no dislocations, and this is a proper way for prevention of dislocation in high‐risk patients. The group of revision THRA with CAL had a high dislocation rate (35%). Abductor muscle weakness below grade 3 was a risk factor for failure of CAL for hip dislocation. We recommend treating patients with recurrent dislocations with the presence of abductor muscle weakness below grade 3 with not only THRA using CAL but also applying additional abductor muscle reconstruction to reduce the risk of dislocation.

In this study, we evaluated how muscle mass and bone density affect postoperative functional scores and subsequent fracture rates and investigated the correlation between sarcopenia and osteoporosis by measuring preoperative psoas muscle indices (PMIs) and bone mineral densities (BMDs) in elderly patients followed for more 1 year after surgical treatment for hip fracture. Among patients older than 65 years who underwent surgery for hip fracture from January 2009 to November 2018, 154 patients with preoperative 3D pelvic bone computed tomography and dual-energy X-ray absorptiometry BMD data and followed postoperatively for at least 1 year were considered for the present study. One hundred twenty-six patients were finally included. These patients were divided into 4 groups based on PMIs and T-score, that is, to osteoporosis, sarcopenia, osteosarcopenia, or normal groups. To analyze outcomes after surgery, we measured functional activity levels using the Barthel index and Harris hip score (HHS) systems. In addition, we compared the rates of subsequent hip fracture ratio with patient’s characteristics, and analyzed the correlation between PMIs and BMDs using Pearson correlations analysis. Barthel index and HHS score showed significant differences between the normal and osteosarcopenia group at 6 weeks, 3 months, and 1 year after surgery (P < .001). Subsequent fracture incidences were significantly higher in the osteosarcopenia group than in the normal group (P = .046), and T-score and PMI were found to be strongly correlated (a < 0.01; R = 0.763). Postoperative functional outcomes were significantly poorer and the subsequent fracture rate was significantly higher in the osteosarcopenia group than in the normal group. In addition, sarcopenia and osteoporosis were found to be highly correlated.

Moon KH, et al. Yonsei Med J. 2008 Oct;49(5):719-724. http://dx.doi.org/10.3349/ymj.2008.49.5.719

The purpose of this study was to evaluate the clinical and radiologic outcomes of young patients (under the age of 30) who received a total hip arthroplasty (THA) and in whom patients had been followed for more than 10 years. This retrospective study was conducted for 51 hips (44 patients) that had undergone THA. The mean age for the index operation was 25.71 years, and the mean follow-up period was 13.7 years. Clinical outcomes were evaluated by Harris hip score (HHS), activity level, and complications. Radiographic evaluations were assessed according to osteolysis, loosening, and polyethylene wear. The average HHS improved from 67.47 pre-operatively to 97.42 at the final follow-up (p < 0.001). The activity level changed from 1.92 pre-operatively to 1.33 at the final follow-up (p < 0.001). Ten cases had undergone revision arthroplasty within the follow-up period, and the overall survival rate was 80.4% at the final follow-up with revision for any reason as the end point. Polyethylene liners were used in all revision cases (p = 0.003). Patients with modular stem had a higher failure rate than patients with a fully porous coated stem (p < 0.001). Furthermore, a small diameter head size was associated with a higher risk of revision surgery (p = 0.003). Complications such as dislocations were found in three hips. Cementless THA yields encouraging clinical and radiological results in young and active patients under the age of 30. However, the bearing surface, type of stem, and head size influenced component durability and revision rate.