Original first metatarsophalangeal hemiarthroplasty and installation technique in treatment of grade 3–4 hallux rigidus

Introduction Arthrodesis is the “gold standard” for the treatment of stage 3–4 osteoarthritis of the first metatarsophalangeal (MTP) joint. However, restricted movements in the joint can lead to changes in the biomechanics of the foot overloading the adjacent joints and are accompanied by decreased activity which is important for younger patients. The available implants of the first MTP joint have some disadvantages and an original hemiarthroplasty of the first MTP joint was developed. The objective was to demonstrate an original technique of hemiarthroplasty of the first MTP joint and installation to treat stage 3–4 hallux rigidus. Material and methods The hemiendoprosthesis is made of zirconium ceramics. The head of the hemiendoprosthesis is made with a low profile. The cross-section of the stem has a four-bladed shape to ensure rotational stability of the implant. The hemiendoprosthesis can be placed using specially designed instruments. A case of a 74-year-old patient diagnosed with stage 3 osteoarthritis of the first MTP joint is reported. Results AOFAS Hallux scored 28 and 95, VAS scored 9 and 0 and FFI scored 112 and 6 preoperatively and at 24 months, respectively. The range of motion in the joint (extension/flexion) measured 0°–0°–5° preoperatively and 60°–0°–15° at 24 months. The dynamic pedobarography indicated to the physiological distribution of pressure in the foot being restored postoperatively. Discussion The first implants offered to replace first MTP joint were made of silicone and metal alloys and total joint arthroplasty was associated with significant resection of bone tissue; cases of endoprosthetic instability were reported. Hemiarthroplasty appeared to be a sparing technique. However, implants made of metal alloys could have an aggressive effect on the opposite articular surface. Hemiarthroplasty of the first MTP joint using a zirconium ceramic implant could minimize the risk of the complications. Conclusion Hemiarthroplasty of the first MTP joint using an original zirconium ceramic implant was shown to be effective for patients with stage 3–4 hallux rigidus. The technique reported can be a good alternative to arthrodesis of MTP joint.