Resurfacing of the Metatarsal Head to Treat Advanced Hallux Rigidus

摘要

The HemiCAP prosthesis is a novel approach to the treatment of arthritis of the first MTP joint because it resurfaces the metatarsal head. Studies have shown a better range of motion, greater pain reduction, and higher patient satisfaction with this technique when compared with the other implant hemiarthroplasties.(13,14) One possible explanation is that the metatarsal head is usually the more involved side of the MTP joint degeneration in hallux rigidus. Resurfacing the metatarsal side would therefore address the more-advanced cartilage destruction and provide better pain relief. Furthermore, impaction of the proximal phalanx on the metatarsal head could be a major causal factor for pain generation in hallux rigidus. Hemiarthroplasty techniques that resurface the proximal phalanx still leave a damaged metatarsal head surface. The impaction of the implant onto the remaining damaged metatarsal head could be a major cause for persistent pain with those implants. Technically the implant can be advanced further into the metatarsal head by several millimeters allowing for decompression of the joint and reduction of impact forces. This technique of decompressing the joint has been previously described by others as a means of relieving joint stresses.(2,5,29)