Correlative Study Of Transfer Metatarsalgia Of Hallux Valgus After Distal Osteotomy Of The First Metatarsal

Objectives: The aims of this study were to investigate the radiological change and the distribution of plantar pressure after distal osteotomy of the first metatarsal ,to discuss correlative factors of transfer metatarsalgia postoperatively and to find dangerous factors of transfer metatarsalgia, which will be some basis for treating and providing for transfer metatarsalgia.Methods:1. 91cases of hallux valgus (including 79 female,74 left feet,68 right feet; 12men,9 left feet,10 right feet) have undergone distal osteotomy of the first metatarsal were examined by X-ray on weightbearing and lateral position before and after operation. Several parameters,including HVA,IMA ,the wideth of forefoot, Peak Pressure and Pressure Time Integral,were measured and AOFAS score was carried out.2. Several parametes above are analysed between all patients preoperatively and postoperatively. Such as were between patients with metatarsalgia preoperatively and patients without metatarsalgia preoperatively, between patients with metatarsalgia preoperatively and postoperatively, between patients with metatarsalgia preoperatively and without metatarsalgia postoperatively, between patients with metatarsalgia postoperatively and patients without metatarsalgia postoperatively.3. The total of 24 cases of hallux valgus with 48 feet were choosed at random. Forefoot plantar pressure were measured during waking by Footscan system preoperatively and postoperatively.The forefoot was divided five regions according to the five metatarsals. Peak Pressure and Pressure Time Integral of the five regions and Percentage of Peak Pressure and Pressure Time Integral of the every region were compared preoperatively and postoperatively to evaluate the plantar pressure changes while walking. Results:1. Compared with preoperatively and postoperatively weighbearing X-ray measurement ,HVA was reduced to 9.58°±5.07°,form 33.71°±8.44°.IMA was 7.52°±1.95°,form 12.65°±2.94°.The length of the first metatarsal was 54.04mm±5.97mm form 57.10mm±4.90mm .The width of forefoot was 70.93mm±8.06mm form 87.28mm±6.70mm.The parameters are statistical significance. HVA and IMA was close to the normal value. when the therapeutic effect of the 161 feet were evaluated , 144 feet were excellent, 12 were good and 5 poor. AOFAS score was 82.4 while 57.8 preoperatively.There were Correlation among HVA ,IMA and the width of forefoot.2. Comparing patients with metatarsalgia preoperatively and patients without metatarsalgia preoperatively, HVA had statistical significant differences,IMA ,the width of forefoot,the length of the first and second metatarsal and the relative metatarsal protrusion between the first and second metatarsal had no statistical significant differences. Comparing patients with metatarsalgia preoperatively and without metatarsalgia postoperatively,HVA,IMA ,the width of forefoot,the length of the first metatarsal and the relative metatarsal protrusion between the first and second metatarsal had had statistical significant differences. Comparing patients with metatarsalgia preoperatively and postoperatively,HVA, the width of forefoot and the relative metatarsal protrusion between the first and second metatarsal had statistical significant differences,IMA and the length of the first metatarsal had no statistical significant differences. Comparing patients with metatarsalgia postoperatively and patients without metatarsalgia postoperatively, the width of forefoot, the length of the first and second metatarsal had statistical significant differences,HVA,IMA and the relative metatarsal protrusion between the first and second metatarsal had no statistical significant differences.3. Pressure Time Integral and Peak Pressure among five regions are maxium under the second or third metatarsal preoperatively. PTI and PP of under the second , third and fourth metatarsal reduced postoperatively. PTI and PP of under the first and fifth metatarsal increased. Peak Pressure under the first, second and third metatarsal was statistical significance preoperatively and postoperatively. There was no statistically significant differences under the fourth and fifth metatarsal. Pressure Time Integral under the first,second,third and fifth metatarsal was statistical significance preoperatively and postoperatively , There was no statistically significant differences under the fourth metatarsal.Conclusion:1. There was correlation between metatarsalgia and HVA, The relative metatarsal protruion of between the first and second metatasal, The width of the forefoot. More larger is HVA, More come into being metatarsalgia; More larger is The relative metatarsal protruion of between the first and second metatasal, More come into being metatarsalgia; More widther is the forefoot, More come into being metatarsalgia.2. Excessive shortening of the first metatarsal may result in transfer metatarsalgia after distal osteotomy of the first metatarsal.3. If Hallux valgus was the relative shortening of the first metatarsal ,we should be avoid osteotomy; another ,we can adopt osteotomy.