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Use of Human Perivascular Stem Cells for Bone Regeneration
Published on: May 25, 2012
Use of a hydroxyapatite-coated stem in patients with Dorr Type C femoral bone
Stephen J Kelly1, Claire E Robbins, Benjamin E Bierbaum
1Orthopaedic Associates of Portland, PA, Portland, ME, USA.
Insights
Hydroxyapatite-coated stems show promising results for total hip arthroplasty in patients with Type C bone, a challenging bone quality. This study found the Omnifit HA stem performed well over a 9-14 year follow-up.
Area of Science:
- Orthopedic Surgery
- Biomaterials Science
- Bone Biology
Background:
- Type C bone presents significant challenges for total hip arthroplasty (THA) fixation due to cellular and structural compromise.
- Hydroxyapatite (HA) coatings are utilized to enhance bone integration and implant stability.
- Evaluating long-term outcomes of HA-coated stems in compromised bone is crucial for clinical decision-making.
Purpose of the Study:
- To evaluate the clinical and radiographic performance of the Omnifit HA stem in patients with Type C femoral bone undergoing primary total hip arthroplasty.
- To assess the long-term survivorship and functional outcomes of this specific HA-coated stem in a challenging bone quality cohort.
Main Methods:
- Retrospective review of 15 patients with Type C bone who received the Omnifit HA stem between 1991 and 1994.
- Minimum 9-year follow-up (mean 11.5 years) including clinical assessment (Harris hip score) and radiographic evaluation.
- Independent radiographic review to confirm Type C bone classification and assess for osteolysis and subsidence.
Main Results:
- The Omnifit HA stem demonstrated favorable clinical outcomes with a median Harris hip score of 94.5 points.
- Radiographic analysis confirmed Type C bone in all patients, with an average canal to calcar isthmus ratio of 0.74.
- At 9-14 years, no distal osteolysis or subsidence was observed; four patients showed proximal osteolysis.
Conclusions:
- The Omnifit HA stem performed well in a selected group of patients with Type C bone, offering good functional outcomes and radiographic stability.
- Results compare favorably to previous studies using this stem design in other bone types.
- These findings support the use of hydroxyapatite-coated stems for total hip arthroplasty in patients with compromised Type C bone quality.
Abstract:
Type C bone, as described by Dorr, exhibits both cellular and structural compromise, which presents a challenge for fixation of a total hip arthroplasty (THA). We evaluated the performance of the Omnifit HA stem, a hydroxyapatite-coated titanium alloy stem, by retrospectively reviewing the clinical and radiographic data of 15 patients with femoral Type C bone who received the stem during primary THA between 1991 and 1994. The patients were followed a minimum of 9 years (mean, 11.5 years; range, 9-14 years). The average age at surgery was 54 years and the average body mass index was 28. Eight of the patients were men. The median Harris hip score was 94.5 points. Radiographically, two independent reviewers identified all patients as Type C bone. The average canal to calcar isthmus ratio was 0.74 (range, 0.65-0.95). At most recent followup, four patients demonstrated proximal osteolysis. Using plain radiography we detected no patients with distal osteolysis or subsidence. At 9 to 14 years, the stem has performed well in a selected series of patients with poor bone quality and the outcomes compare favorably with previously reported findings using this design of stem in other bone types. These results support the decision to use a hydroxyapatite-coated stem in patients with Type C bone.
