Does Decompressive Chevron Osteotomy Decrease Subchondral Bone Density of the First Metatarsophalangeal Joint in Hallux Rigidus?

Background: To investigate the impact of decompressive chevron osteotomy on subchondral bone density at the first metatarsophalangeal (MTP) joint. Methods: Sixteen feet (12 patients) with hallux rigidus underwent decompressive chevron osteotomy. Standing cone beam 3D computed tomography (3DCT) were assessed preoperatively and at 4-month follow-up, and clinical data were collected. Radiologic measurements, including bone density using Hounsfield units (HU), were conducted. Statistical analyses were performed to evaluate changes and correlations. Results: Postoperative bone density significantly decreased in proximal (Pre, 650.9 ± 149.1; Post, 312.4 ± 115.9; P < .001) and distal (Pre, 910.4 ± 143.3; Post, 639.0 ± 167.1; P < .001) components of the first MTP joint and the first tarsometatarsal (TMT) (Pre, 762.9 ± 166.6; Post, 611.5 ± 165.9; P < .001) joint. No significant difference was measured at the tibiotalar joint (Pre, 497.5 ± 143.6; Post, 534.3 ± 130.7; P = .065). Length of the first metatarsal (Pre, 60.4 ± 3.4; Post, 54.3 ± 3.0; P < .001) and metatarsal protrusion index (MPI) (Pre, −0.9 ± 3.0; Post, −9.0 ± 3.6; P < .001) significantly decreased postoperatively. Clinical assessments showed significant improvements in pain on the visual analog scale (−5.3 ± 1.9). Conclusion: Decompressive chevron osteotomy leads to a significant decrease in subchondral bone density of the first MTP joint. A decrease in bone density occurs also in the first TMT joint. Level of Evidence: Level IV, radiographic study.