Background: The ultrasound-guided viscosupplementation of the hip joint with hyaluronic acid (HA) is considered a standard procedure among the conservative treatments for hip arthritis. The aim of this study was to evaluate the clinical benefit and the incidence of adverse events of the technique in an observational study at one year follow up. Methods: We evaluated a consecutive series of 85 patients with a diagnosis of symptomatic arthritis who underwent intra-articular ultrasound-guided hyaluronic acid injections. The scales used for evaluation were modified Harris Hip Score (mHHS), WOMAC (Western Ontario and McMaster University), and Hip Outcome Score (HOS) with subscale Sport (HOSs), for pain the Visual Analogic Scale (VAS). The patients were classified according to Tonnis’ radiological classification of arthritis (range 0–3): 20 patients (grade 0), 32 (grade 1), 18 (grade 2), 15 (grade 3). Results: At last follow up, all the scales increased: mHHS from 59.35 to 82.1, HOS from 69.45 to 78.53, HOss from 47.4 to 58.11, VAS from 6.09 to 3.97, WOMAC from 33.2 to 31.5 (p < 0.05 for all the parameters); the results were elaborated with GraphPad Prism v5.0 (Prism Software La Jolla, CA, USA) using Wilcoxon’s test. A total of 13 patients out of 85 needed arthroplasty, all classified as Tonnis grade 3. No serious adverse events were noted due to the procedure. Conclusions: Based on our findings, indication for the use of hyaluronic acid is limited to patients with mild to moderate arthritis. Patients in advanced arthritis refusing replacement surgery and asking for this treatment should be informed about the poor results of the technique even in the short term.

Aims: Revision hip arthroplasty for femoral stem loosening remains challenging due to significant bone loss and deformities requiring specialized revision stems. The aim of this study was to evaluate the clinical and radiological outcomes, and survival, of a consecutive series of femoral revisions performed using a primary cementless stem with tapered geometry and rectangular cross-section at medium-term follow-up.Methods: We retrospectively evaluated 113 patients (115 hips) with intraoperative Paprosky type I (n = 86) or II (n = 29) defects, who underwent femoral revision with Alloclassic Zweymüller SL stem for one-stage aseptic revision or two-stage septic revision from January 2011 to December 2020. The mean follow-up was 77.9 months (SD 33.8). Nine patients were lost to follow-up (deceased or not available), leaving 104 patients (106 hips) for the clinical and radiological analysis. Clinical assessment was performed with Harris Hip Score (HHS) and visual analogue scale (VAS) before surgery and at final follow-up.Results: There were 60 males and 53 females with a mean age at time of surgery of 71.2 years (SD 12.6). The mean HHS and VAS significantly improved at final follow-up, from 33.7 (SD 13.0) and 5.8 (SD 1.8) preoperatively to 66.4 (SD 16.8) and 2.1 (SD 1.8) postoperatively, respectively (p = 0.001 and p = 0.001). Overall, 28 patients (25%) showed non-progressive radiolucent lines at the level of proximal femur without radiological or clinical signs of loosening. One patient had a recurrence of periprosthetic joint infection after a two-stage procedure requiring re-revision surgery. One patient underwent exchange of modular components for recurrent dislocation, and another case of dislocation was treated conservatively. The survival with aseptic loosening as endpoint was 100%, while stem revision for any reason was 99.1% at up to 152 months’ follow-up.Conclusion: Alloclassic Zweymüller SL primary stem showed favourable medium-term results and survival for revision total hip arthroplasty in Paprosky type I and II defects.Cite this article: Bone Jt Open 2025;6(2):186–194.

The ultrasound guided viscosupplementation of the hip joint with hyaluronic acid(HA)is considered a standard procedure among the conservative treatments for hip arthritis.The aim of the study was to evaluate the clinical benefit and the incidence of adverse events of the technique in a obseravtional study at one year follow up. We evaluated a consecutive series of 85 patients with a diagnosis of symptomatic arthritis that performed intra-articular ultrasound-guided hyaluronic acid injections. The scales used for evaluation were modified Harris Hip Score(mHHS),WOMAC (Western Ontario and McMaster University),Hip Outcome Score (HOOS) with subscale Sport (HOOSs), for pain the Visual Analogic Scale (VAS).The patients were classified according to Tonnis’ radiological classification of arthrosis (range 0-3):20 patients(grade 0),32(grade 1),18(grade 2),15(grade 3).At last follow up all the scales increased:mHHS from 59.35 to 82.1,HOOS from 69.45 to 78.53,HOS Sport from 47.4 to 58.11,VAS from 6.09 to 3.97,WOMAC from 33.2 to 31.5 (p<0.05 for all the parameters);13/85 requested arthroplasty. Based on our findings, indication for use of hyaluronic acid is limited to patients with mild to moderate arthritis.Patients in advanced arthritis refusing replacement surgery and asking for this treatment should be informed about the poor results of the technique even in the short term follow up.