The Use of a Megaprosthesis in the Management of Stem Loosening after Revision Hip Arthroplasty in a Patient with Extensive Femoral Bone Destruction. Case Study

This paper presents the case of a female patient who underwent eleven revision surgeries after primary hip arthroplasty due to infection and loosening of the stem and acetabulum. We decided that in order to save the limb, it was necessary to use a total femur prosthesis. Three years’ follow-up showed that the patient was satis­fied with the outcome of the surgery.

Cementless Primary or Revision Stem in the First-time Revision Hip Arthroplasty for Aseptic Stem Loosening? A Retrospective Comparative Study.

IntroductionThe use of primary or revision stem during the first-time revision total hip arthroplasty(THA) procedure for aseptic stem loosening remains controversial. The aim of this study was to compare the outcome of patients that underwent revision THA with a primary or revision stem.Materials and MethodsWe retrospectively reviewed 78 patients that received first-time revision THA for aseptic stem loosening using primary(N=28) or revision stems(N=50). The bone defects were classified as Paprosky type I or II. The mean follow-up duration was 72.3±34.7 months. The primary outcome domains included surgical complications and implant failures. The secondary outcome domains included medical complications, 30-day and 90-day readmission, and Harris hip score (HHS).ResultsThe use of revision stem was associated with higher incidence of patient having complications (60.0% vs. 32.1%, p=0.018), including intraoperative femur fracture (28.0% vs. 7.1%, p=0.029) and greater trochanter fracture (16.0% vs. 0%, p=0.045), compared with the use of primary stem. The implant survival was comparable in both groups. HHS at the final follow-up was similar.ConclusionWith a lower risk of surgical complication and similar mid-term implant survival, cementless primary stem might be a better alternative to revision stem in the first-time revision THA for aseptic stem loosening.

Inadvertent, intraoperative, non- to minimally displaced periprosthetic humeral shaft fractures in RTSA do not affect the clinical and radiographic short-term outcome

Introduction Little information is available on the clinical and radiographic outcome of intraoperative, non- to minimally displaced humeral fractures that occur during implantation of a stemmed, reverse shoulder prosthesis but are only recognized on routine postoperative radiographs. The goal of this study is to report the clinical and radiographic outcome for this rarely reported fracture type. Materials and methods 39 conservatively treated non- to minimally displaced intraoperative periprosthetic humeral fractures after stemmed RTSA were detected from our radiographic database between 1.1.2006 and 31.1.2018. Exclusion criteria were lack of patient consent, preoperative humeral fracture, and revision arthroplasties. Clinical (absolute and relative Constant score, the Subjective Shoulder Value) and radiographic (conventional radiographs) assessment was performed preoperatively, at 6 weeks (only radiographically) and at latest follow-up with a minimum follow-up of 2 years. Results 35 patient’s with a mean age of 72 years (range 32–88, SD ± 11 years) and a mean follow-up of 53 months (range 24–124, SD ± 31) were included in the study. At latest follow-up, all clinical outcome parameters except external rotation improved significantly. A complication rate of 17% (n:6) was recorded. At 6 weeks after the index surgery, none of the radiographs showed a fracture displacement or a sintering of the stem. At latest follow-up, all fractures were healed and no stem loosening was observed in any of the shoulders. Conclusions Non- to minimally displaced intraoperative periprosthetic humeral fractures in RTSA have an incidence of about 5% in this series of mainly uncemented press-fit stems. They generally heal without any further treatment and are not associated with stem loosening or compromise the clinical outcome after primary RTSA. Except slight restriction in the postoperative rehabilitation protocol, no further attention or action is needed.

Automated Femoral Stem Canal Fill Ratio Evaluation for Bipolar Hip Arthroplasty in 2D X-Ray Image

A stem loosening is one of the significant problem in the bipolar hip arthroplasty (BHA), causes a pain and instability of a patient’s hip, and requires a further surgery of BHA. A stem canal fill ratio (SCFR), a general evaluation of the stem loosening, have been clinically studied many; however, a determination of the optimal SCFR evaluation has not been still understood well. A purpose of this study is to propose an automatic and quantitative evaluation of SCFR from BHA hip X-ray image. A proposed method segmented the femoral canal and stem, and evaluated SCFR. In experiments, a proposed method’s accuracy was validated, and six BHA patients’ SCFRs were clinically evaluated (age 88±7 (74–93), one male / five females). In result of the proposed method’s accuracy, the femur canal was 90.60±3.65%, and the stem was 97.83±0.46%; therefore, the proposed method had the accuracy to well evaluate SCFR. Result of six BHA patients’ SCFRs was 63.70±5.62%. In conclusion, the proposed method was able to automatically evaluate SCFR from the hip X-ray image with BHA.

Risk factors for loosening of cementless threaded femoral implants in canine total hip arthroplasty

SummaryObjective: To determine the incidence and potential risk factors of femoral implant loosening in the canine Helica® total hip replacement (THR) system.Method: Sixteen dogs with a Helica THR were included. Medical records were reviewed for signalment and size of implants. Stem angle, stem collar to lateral cortex distance, tip to cortex distance, stem collar to lateral cortex distance at a stem angle of 150°, lever arm distance, and the distance on the diaphysis measurements were calculated from the one year postoperative radiographs. Three ratios were determined from these measurements to take into account the size of the femur in relation to the size of the implant. Femoral implant loosening was identified by radiographic and clinical signs, and confirmed at the time of surgical explantation. Differences in the successful and fe-moral stem failure groups were compared using either a students t-test or a Mann Whitney test. Significance was set at p <0.003.Results: Six of the 16 dogs had loosening of the femoral prostheses within one year post-implantation. One dog had evidence of a septic cause for loosening. No significant risk factors could be identified in this group of dogs with Helica stem loosening.Clinical significance: Helica femoral stem loosening was a common complication within one year post-implantation in this group of dogs. No risk factors were identified to potentially decrease the incidence of loosening. Therefore, due to this unacceptably high complication rate, the authors do not recommend this model of the Helica THR.