Liet day than kinh hong khoeo ngoai chiem 0,50% benh than kinh (Ho Htfu Ltfdng, Nguyen Van Chtfdng, Cao Htfu Han 1991).
1. Giai phau
Day than kinh hong khoeo ngoai (hay day mac chung la day hon hdp, la mot trong 2 nhanh tan cua day than kinh hong to, xuat phat ttf nhtfng sdi cua re L4, L5, Si (hinh 6.9).
Day than kinh hong khoeo ngoai chay doc theo bd trong cd nhi dau dui, tdi chom xtfdng mac thi chia ra nhanh cung: day than kinh mac nong (day cd bi) va day than kinh mac sau (day than kinh chay trtfdc). Khi day than kinh chay trtfdc qua day chang co chan thi chia ra hai nhanh cung: nhanh trong tach ra 5 nhanh cho ngon chan 1,2 va niia ngon 3; nhanh ngoai tach ra hai nhanh cho niia ngon 3 va niia ngon 4.
La day van dong cac cd duoi ban chan (cd chay trtfdc) cac cd duoi ngon chan (cd duoi chung ngon chan) va cac cd xoay ban chan ra ngoai (cac cd mac).
La day cam giac cua cang chan trtfdc ngoai va mu chan.
2.Trieu chiing
Ban chan ru xoay vao trong dong thdi quay ngUa kieu ban chan ngtfa veo trong (pes eqinovarus) do liet cac cd duoi ban chan va xoay ban chan ra ngoai, trong khi cac cd gap ban chan van binh thtfdng (hinh 6.20).
Dang di chan ru (steppage): khi di phai nhac cao ban chan de khoi quet ban chan xuong dat.
- Khong the di bang got chan va khong the duoi hoac xoay ban chan ra ngoai.
Hinh 6.20: Ban chan ngifa veo vao trong
Hinh 6.21: Phan vung cam giac cua day hong khoeo ngoai
1. Than kinh bi mac2. Than kinh hien mac 2. Than kinh hien mac 3. Than kinh cd bi 4. Than kinh chay trifdc.
Roi loan cam giac mat ngoai cang chan va mu ban chan (hinh 6.21)
3. Nguyen nhan
Day hong khoeo ngoai nam sat chom xtfdng mac nen khi gay xtfdng, day than kinh hay bi cac manh xtfdng cat dtft hoac bi chet trong can (cai) luc tai tao xtfdng.
- La di chtfng sau viem nhieu day than kinh.
- Thtfdng ton than kinh hong khoeo ngoai do bien chtfng dai thao dtfdng.
E. LIET DAY THAN KINH HONG KHOEO TRONG
1. Giai phau
- Day than kinh hong khoeo trong (day than kinh chay) tiep theo htfdng di cua day than kinh hong to va chay theo dtfdng phan giac cua tram khoeo. Doi vdi dong mach va tinh mach thi day than kinih hong khoeo trong la bac thang d nong va d ngoai cung, bac gitfa la tinh mach, bac trong va sau la dong mach (do do Ho Htfu Ltfdng da ap dung phtfdng phap phong be phenol canh day than kinh hong khoeo trong de dieu tri di chtfng co ctfng ban chan). Day than kinh hong khoeo trong di qua cung cd dep thi doi ten la than kinh chay sau (nerf tibial posterieur) tdi sau mat ca trong thi chia ra hai nhanh cung:
Nhanh ben:
+ Day cd (cho cd tam dau cang chan, cd gap chung ngon chan, cd dai, gap ngon chan cai) co chtfc nang gap ban chan va ngon chan (quap ngon chan va ban chan ve phia gan chan) va xoay ban chan vao trong.
+ Day khdp co chan trong
+ Day got trong (rami calcanei medialis) la mot nhanh to phan phoi vao da got.
Nhanh cung:
+ Day gan chan ngoai + Day gan chan trong
2. Trieu chtfng
+ Khong the gap ban chan va ngon chan ve phia gan chan va khong the xoay ban chan vao trong.
+ Ban chan co hinh "ban chan lorn" (pes calcaneus), hinh vuot: cac dot mot ngon chan qua duoi, cac dot hai va ba quap lai, teo cd phia sau cang chan va gan chan, vom gan chan horn sau (hinh 6.22).
+ Dang di nang ne, phai let got chan tren mat dat, khong the nhac got chan len dtfdc (do liet cd tam dau cang chan). Ban chan co khuynh htfdng veo ngtfa ra ngoai va ty bd trong ban chan len mat dat.
+ Khong the di bang dau ngon chan dtfdc.
Hinh 6.22: "Ban chan lorn (Pes calcaneus)
Hinh 6.23: Phan vung cam giac cua day hong khoeo trong