Metal-on-metal hip resurfacing in patients with pigmented villonodular synovitis: a report of two cases

Pigmented villonodular synovitis does not influence the outcome following cementless total hip arthroplasty using ceramic-on-ceramic articulation: a case-control study with middle-term follow-up

Background

Pigmented villonodular synovitis (PVNS) is a relatively rare, locally aggressive, and potentially recurrent synovial disease of large joints. The purpose of this study was to investigate (1) the disease recurrence rate and (2) the treatment outcomes including Harris hip scores, complications, and revision following cementless total hip arthroplasty (THA) with ceramic-on-ceramic (CoC) articulation in patients with PVNS.

Methods

Twenty-two patients (14 females and 8 males) with histologically confirmed PVNS underwent cementless THA using CoC bearings between 2000 and 2013. Three patients with less than 5-year follow-up were excluded. The mean age was 35.2 years (range, 22–58 years) with a mean follow-up of 8.6 years (range, 6.9–10.8 years). A control group was matched in a 2:1 ratio with the PVNS group for age, sex, body mass index (BMI), year of surgery, and American Society of Anesthesiologists score (ASA). Postoperative outcome variables included disease recurrence, Harris Hip Scores (HHS) at the latest follow-up, complications (dislocation, squeaking, ceramic fracture), and any-cause revision. A Kaplan-Meier implant survivorship curve with 95% confidence interval (CI) of the two groups was generated.

Results

No recurrence of PVNS was noted in the follow-up period. The HSS in the PVNS group was 92.6 ± 5.5, which was similar to the control group (93.4 ± 4.6, p = 0.584) at the last follow-up visit. No patients sustained dislocation, osteolysis, or any ceramic fracture within the study duration. One patient in the PVNS group had a complication of squeaking, but did not require revision. Another patient in the PVNS group underwent revision surgery due to aseptic loosening. There was no significant difference in revision rates between the two groups (p = 1.000). The implant survivorship free of any revision was 90.0% (95% CI, 73.2% to 100%) in the PVNS group and 92.5% (95% CI, 82.6% to 100%) in the control group at 10 years (p = 0.99).

Conclusions

For young and active patients with end-stage PVNS of the hips, cementless THA using CoC bearing has similar functional outcome scores, a low complication rate, and similar implant survivorship compared to the control group.

MR imaging of hip arthroplasty implants

Hip arthroplasty has become the standard treatment for end-stage hip disease, allowing pain relief and restoration of mobility in large numbers of patients; however, pain after hip arthroplasty occurs in as many as 40% of cases, and despite improved longevity, all implants eventually fail with time. Owing to the increasing numbers of hip arthroplasty procedures performed, the demographic factors, and the metal-on-metal arthroplasty systems with their associated risk for the development of adverse local tissue reactions to metal products, there is a growing demand for an accurate diagnosis of symptoms related to hip arthroplasty implants and for a way to monitor patients at risk. Magnetic resonance (MR) imaging has evolved into a powerful diagnostic tool for the evaluation of hip arthroplasty implants. Optimized conventional pulse sequences and metal artifact reduction techniques afford improved depiction of bone, implant-tissue interfaces, and periprosthetic soft tissue for the diagnosis of arthroplasty-related complications. Strategies for MR imaging of hip arthroplasty implants are presented, as well as the imaging appearances of common causes of painful and dysfunctional hip arthroplasty systems, including stress reactions and fractures; bone resorption and aseptic loosening; polyethylene wear-induced synovitis and osteolysis; adverse local tissue reactions to metal products; infection; heterotopic ossification; tendinopathy; neuropathy; and periprosthetic neoplasms. A checklist is provided for systematic evaluation of MR images of hip arthroplasty implants. MR imaging with optimized conventional pulse sequences and metal artifact reduction techniques is a comprehensive imaging modality for the evaluation of the hip after arthroplasty, contributing important information for diagnosis, prognosis, risk stratification, and surgical planning.