Severe hallux rigidus can be treated with total or hemi arthroplasty to preserve motion in the 1st metatarsophalangeal joint (MTPJ). Decreased dorsiflexion impairs the rollover motion of the 1st MTPJ and recent studies of patients with 1st MTPJ osteoarthritis show increased plantar forces on the hallux. Our aim was to examine the plantar force variables under the hallux and the 1st, 2nd, and 3rd – 5th distal metatarsal head (MH) on patients operated with a proximal hemiarthroplasty (HemiCap) in the 1st MTPJ and compare to a control group of healthy patients. Secondary aims: To examine correlations between the force and the 1st MTPJ range of motion (ROM) and pain.Background
Objectives
Hallux rigidus in the metatarsophalangeal joint (MTPJ) can be treated with arthroplasty to reduce pain and enhance motion. Few studies have investigated the functionality and the survival of HemiCap arthroplasty. Primarily we aimed to examine the medium to long-term functionality and the degree of pain after surgery. Secondarily the failure and revision rate of HemiCap implants. A total of 106 patients were operated with HemiCap arthroplasty (n=114) from 2006 to 2014, median age 53 (16 to 80) years, 78 females, 37 dorsal flange (DF) implants. Patient charts were reviewed retrospectively to collect revision data. Pre operative Coughlin/Shurnas arthrosis degree, hallux valgus (HV), intermetatarsalintermetatarsal (IM) and Distal Metaphyseal Articular Angle (DMAA) angles was were measured. Pre- and post operative 3 weeks, 6 months, 1 and 2 year2-year pain levels of the first MTPJ by Visuel Analog Skala (VAS 1–10), American Orthopaedic Foot and Ankle Score (AOFAS 0 to 100 points) and, Range of Motion (ROM), were available for 51 patients. FortysevenForty-seven of the 70 available for reexamination partook in a cross sectional follow up where the Self-Reported Foot and Ankle Score (SEFAS 0–48 points) was added to the Patients Related Outcome Measures (PROMs).Background and aims
Methods
Increase in heel height increases peak pressure under the forefoot. Customized shoe inlays with metatarsal lift, arch support has demonstrated lowered forefoot pressure and increase in the subjective comfort. A commercial shoe brand (Roccamore) has introduced an off-the-rack stiletto with a slim (1 cm2) 8 cm heel plus 2 cm platform with metatarsal lift, arch support and heel cap claiming it will reduce the discomfort associated with high heels. The primary aim of this study was to compare the pressure under the forefoot, arch, heel and toes in this “orthopaedic” stiletto (OS) to a standard stiletto of the same heel height without inlays (SS) and a control sneaker (SN). Secondary aims were to measure the comfort under the forefoot, heel and arch during everyday use. Finally to investigate if any pressure measurements were correlated to comfort or any anatomical/clinical feature of the foot. 22 women, aged 40 (21–62), accustomed to stilettos, walked at 4 km/hr on a level treadmill in all three shoe types. Peak pressure (kPa) and pressure-time integral (kPa/sec) under 2+3rd and first metatarsal heads, the arch/midfoot and heel were measured during 10 consecutive steps at 50 Hz using Novel Pedar-X pressure distribution insoles. Standing X-rays and a standardized clinical examination were carried out. Mundermanns comfort VAS and daily steps were recorded for each shoe type during 3 full days. (0= worst to 150 mm= most comfortable). Data were compared with paired t-tests and regression analysis. Statistical significance is reported as p<0.05=, p<0.01=, p<0.001=. Peak pressure: Compared to SS the peak pressure under the 2+3 metatarsals was reduced to 82% in the OS and 60% in the SN. Under the first metatarsal it was reduced to 73% and 40%, respectively. Under the arch it was similar for SN and OS and 30% lower for the SS. Under the heel the OS was 27–28% lower than SS and SN. The same reductions, as well as similarities in the arch were seen in the pressure-time integrals, although with smaller difference between OS and SS, and conversely larger reductions in the SN to 49% under 2+3 metatarsals and 43% under the first. For forefoot, arch and heel, the comfort was rated highest for the SN and lowest for the SS. No statistical difference between OS and SS in the arch. For each mm the second metatarsal was longer than the first, the peak pressure under MT2+3 rose 13 kPa (95%CI: 7 to 19) and the pressure time integral 3 kPa/s (1–5). No effect of first ray ROM or stability. The forefoot VAS score dropped (less comfortable) 0.3 mm for each kPa/s the pressure time integral rose under the MT2+3. Peak pressure parameters or daily steps were not statistically significantly related to the forefoot comfort. A mass produced “orthopaedic” stiletto can reduce the pressure approaching those achieved in a sneaker and increase comfort for the user. An increase in pressure-time integral under 2+3 metatarsals increases the discomfort and the pressure is increased in index-minus feet.
