Hip preserving procedures for osteonecrosis of the femoral head after collapse

Zoledronic Acid and Enriched Autologous Bone Marrow Stem Cell Implantation for Femoral Head Osteonecrosis

Purpose

This study evaluated the clinical results of zoledronic acid in the treatment of early osteonecrosis of the femoral head (ONFH).

Materials and Methods

Study retrospectively analyzed 60 patients with zoledronic acid with bone marrow stem cell (BMSC) implantation (The study group) and 64 patients with BMSC implantation (The control group). The primary evaluation index included VAS, HHS, collapsed rate, and total hip replacement arthroplasty (THA) conversion rate.

Results

The study group had a lower VAS (1.12 ± 0.22 vs 1.44 ± 0.32) and higher HHS (75.07 ± 3.66 vs 68.78 ± 2.24) compared to the control group in 6 months after surgery (P < 0.05). In the study group, 12 hips (20%) collapsed, and 7 of 60 hips (11.67%) required THA surgery at the last follow-up. However, 25 hips (38.8%) collapsed in the control group, and 19 hips (29.69%) required THA surgery. The study group had a lower collapsed rate (P = 0.029) and THA conversion rate (P = 0.016) in survival analysis.

Conclusion

Zoledronic acid and BMSC implantation in the treatment of early ONFH is safe and effective, reduces pain shortens recovery time, and reduces collapsed rate and THA conversion rate in ONFH patients.

Management of chondral and osteochondral lesions of the hip : A comprehensive review

Chondral and osteochondral lesions encompass several acute or chronic defects of the articular cartilage and/or subchondral bone. These lesions can result from several different diseases and injuries, including osteochondritis dissecans, osteochondral defects, osteochondral fractures, subchondral bone osteonecrosis, and insufficiency fractures. As the cartilage has a low capacity for regeneration and self-repair, these lesions can progress to osteoarthritis. This study provides a comprehensive overview of the subject matter that it covers. PubMed, Scopus and Google Scholar were accessed using the following keywords: "chondral lesions/defects of the femoral head", "chondral/cartilage lesions/defects of the acetabulum", "chondral/cartilage lesions/defects of the hip", "osteochondral lesions of the femoral head", "osteochondral lesions of the acetabulum", "osteochondral lesions of the hip", "osteochondritis dissecans," "early osteoarthritis of the hip," and "early stage avascular necrosis". Hip osteochondral injuries can cause significant damage to the articular surface and diminish the quality of life. It can be difficult to treat such injuries, especially in patients who are young and active. Several methods are used to treat chondral and osteochondral injuries of the hip, such as mesenchymal stem cells and cell-based treatment, surgical repair, and microfractures. Realignment of bony anatomy may also be necessary for optimal outcomes. Despite several treatments being successful, there is a lack of head-to-head comparisons and large sample size studies in the current literature. Additional research will be required to provide appropriate clinical recommendations for treating chondral/osteochondral injuries of the hip joint.

High-Degree Valgus Osteotomy for Severe Femoral Head Osteonecrosis After Femoral Neck Fracture with Nonunion: A Case Report

CASE

A 15-year-old adolescent boy had severe groin pain because of extensive osteonecrosis of the femoral head with collapse, joint space narrowing, and nonunion after a failed internal fixation for femoral neck fracture. We performed a 60° valgus osteotomy that moved the posteromedial small viable portion of the femoral head to the weight-bearing acetabular area. The femoral neck nonunion and the necrosis healed completely, and the spherical contour of the femoral head was regained after postoperative hip joint remodeling.

CONCLUSIONS

Good remodeling and congruency were achieved by performing high-degree valgus osteotomy to obtain sufficient viable area below the acetabular roof.

A Pilot Experiment to Measure the Initial Mechanical Stability of the Femoral Head Implant in a Cadaveric Model of Osteonecrosis of Femoral Head Involving up to 50% of the Remaining Femoral Head

Background and Objectives: Currently, only patients with osteonecrosis of the femoral head (ONFH), who had bone defects involving 30–33.3% of the remaining femoral head, are indicated in hip resurfacing arthroplasty (HRA). In an experimental cadaver model of ONFH involving up to 50% of the remaining femoral head, the initial stability of the femoral head implant (FHI) at the interface between the implant and the remaining femoral head was measured. Materials and Methods: The ten specimens and the remaining ten served as the experimental group and the control group, respectively. We examined the degree of the displacement of the FHI, the bonding strength between the FHI and the retained bone and that at the interface between the FHI and bone cement. Results: Changes in the degree of displacement at the final phase from the initial phase were calculated as 0.089 ± 0.036 mm in the experimental group and 0.083 ± 0.056 mm in the control group. However, this difference reached no statistical significance (p = 0.7789). Overall, there was an increase in the degree of displacement due to the loading stress, with increased loading cycles in both groups. In cycles of up to 6000 times, there was a steep increase. After cycles of 8000 times, however, there was a gradual increase. Moreover, in cycles of up to 8000 times, there was an increase in the difference in the degree of displacement due to the loading stress between the two groups. After cycles of 8000 times, however, such difference remained almost unchanged. Conclusions: In conclusion, orthopedic surgeons could consider performing the HRA in patients with ONFH where the bone defects involved up to 50% of the remaining femoral head, without involving the femoral head–neck junction in the anterior and superior area of the femoral head. However, more evidence-based studies are warranted to justify our results.