In the current study we present a series of 30 patients who suffered from HR and underwent an MTPJ1 fusion with an IOFix device. Using this technique a very high fusion rate was achieved, although it wasn’t superior, and might have been even inferior to fusion rates with other implants. None of our patients had requested a hardware removal due to a prominent hardware during a minimum two years follow up. For our knowledge this is the largest series that was thus far published on HR patients who were operated by this implant. In a previous similar study on 21 patients by Singhal et al, the use of IOFix allowed a 95% union rate. They too did not report on patients who requested an elective hardware removal. In a former preliminary series of 12 patients who were operated by an IOFix implant, the union rate was reported to be 91.67%. These two studies along with the current indicate reproducible union rates.
In the united states HR with arthritic changes is diagnosed in 2.5% of the population that is older than 50 years. The pathophysiology of the disease is unclear. There are reports of familial history, but trauma, improper shoe wear,  a tight Achilles tendon, or an elevated 1st metatarsus were also proposed as possible triggers for the disease. In a series of 114 HR patients almost four of every five patients have developed a bilateral disease, and 95% percent of the patients with a family history have eventually developed symptoms in the contralateral foot. The most common presenting symptoms were found to be a local pain, and a decreased range of motion. Physical examination often revealed a local tenderness, a dorsal bump, and a decreased range of motion.  A grind test exacerbated pain. Standing radiographs can reveal degenerative changes that include metatarsal head flattening and widening, subchondral sclerosis, osteophytes and subchondral cysts, joint space narrowing, and eventually a joint destruction.
On the basis of the aforementioned clinical and radiographical findings Coughlin and Shurnas have published a grading system according to which a treatment scheme was proposed. In their protocol non-surgical treatment was offered only for those patients who did not have any radiographical findings (grade 0). We on the contrary have offered a primary non-surgical treatment to all of our patients as the first line of treatment for a period of three months. This treatment included Local anti-inflammatory drugs, activity modification (avoiding tip toe standing, avoiding use of flexible sole shoes), and insoles with a morton extension. The data on the patients who have had radiographic signs of HR and were satisfied with a non-surgical treatment is beyond the scope of this article. Coughlin and Shurnas offered a cheilectomy procedure to all grade 1–3 patients, and added an arthrodesis as an option for grade 3 patients. Grade 4 patients were treated by an arthrodesis. We have included grades 1–3 into the same “Moderate” group and have made the decision of whether to conduct a cheilectomy or an arthrodesis during operation according to the cartilage appearance. This was similar to the way Coughlin and Shurnas treated grade 3 patients. Severe cases, which were equivalent to Coughlin and Shurnas grade 4 were treated by an arthrodesis procedure using an IOFix implant. We found this simplification of their grading system to be more applicable to the daily practice and similarly useful when treatment decisions were done.
A few modalities have been used in order to fuse the MTPJ1. With the use of plate and screws (cost ~ 800 to 1200 Euro) in 233 feet, surgeons have obtained union in 230 (98%) joints. Three (1.3%) of these 230 patients have suffered from a prominent hardware and underwent a secondary surgery for hardware removal. 26 (11.3%) patients have had minor complications (superficial wound infection, hematoma/seroma or mild wound dehiscence). With the use of staples (cost ~ 600 Euro per 1 staple. At least two screws are usually needed), union was achieved in 29 (96.7%) out of 30 feet. None of the 29 implants was removed. When two parallel screws (cost ~ 200 Euro per 1 headless screw) were used in 60 feet a union rate of 100% was achieved and no hardware removal was reported. Two crossed screws have led to a 93.3% union rate. When only one intramedullary screw was used in 109 feet, union was achieved in 104 (95.4%) joints, but 85 (78%) of these patients have undergone a hardware removal due to a prominent hardware. This removal rate was exceptional, and alarmingly high. The last article was later criticized both for the questionable surgical technique and the authors’ determination for “fusion”. Altogether, it seems that all fixation devices allowed similar fusion rates, and despite one report the removal rate was very low. Since the IOFix (cost ~ 2000 Euro) was more expensive, and did not allow superior results, its cost-effectiveness is questionable.
Biomechanically, the IOFix device was previously found to be superior over the crossed pins and the dorsal plate device. In vitro it was shown to sustain higher loads, to be stiffer and to sustain a more narrow inter-fragmentary space. In another biomechanical study the IOFix was found to be superior in producing primary inter-fragmentary compression forces but inferior in failure susceptibility when compared to dorsal or plantar plates.
The main weakness of this study is its retrospective and non-comparative fashion. Two patients were lost to follow-up. Although this is the largest series of its kind thus far, it is still a comparatively small patient group. Therefore, we might have had too few patients than the “number needed to harm”, when the need for reoperation was studied.