Drop finger caused by 8th cervical nerve root impairment: a clinical case series.
Recently, it has been reported that impairment by an 8th cervical nerve root lesion can cause drop finger, namely C8 drop finger. Here, we report a clinical case series of C8 drop finger to reveal the clinical outcome of surgical treatments to allow for a better choice of treatment.



The present study included 17 consecutive patients who were diagnosed as having C8 drop finger, in which muscle strength of the extensor digitorum communis (EDC) showed a manual muscle testing (MMT) grade of 3 or less. We retrospectively investigated the clinical characteristics of C8 drop finger and recovery of muscle power was measured by subtraction of preoperative MMT of the EDC from the final follow-up values.



Nine cases showed recovery of muscle power of EDC, whereas the remaining eight cases did not show any recovery including two cases of deterioration. None of the conservatively treated patients showed any recovery. Surgically treated cases included two cases of deterioration. In the cases showing recovery, recovery began 9.9 months after surgery on average and recovery took 13.8 months after surgery on average. There was a significant difference in the recovery of MMT grade between the groups treated conservatively and surgically (p = 0.049). Preoperative MMT grade of EDC showed a moderate correlation with postoperative recovery (r2= 0.45, p = 0.003). In other words, the severity of preoperative muscular weakness correlated negatively with postoperative recovery.



C8 drop finger is better treated by surgery than conservative therapy.
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan. masaokod@gmail.com.
Masao
0000-0003-0982-5386
M
Koda
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
Takeo
T
Furuya
Department of Orthopedic Surgery, Chiba Aoba Municipal Hospital, Chiba, Japan.
Tomoyuki
T
Rokkaku
Department of Orthopedic Surgery, Chiba Aoba Municipal Hospital, Chiba, Japan.
Masazumi
M
Murakami
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
Yasushi
Y
Ijima
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
Junya
J
Saito
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
Mitsuhiro
M
Kitamura
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
Seiji
S
Ohtori
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
Sumihisa
S
Orita
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
Kazuhide
K
Inage
Department of Orthopedic Surgery, University of Tsukuba, Ibaraki, Japan.
Masashi
M
Yamazaki
Department of Orthopedic Surgery, Chiba Aoba Municipal Hospital, Chiba, Japan.
Chikato
C
Mannoji
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005385:Fingers / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011843:Radiculopathy / Q000503:physiopathology / Q000601:surgery; D012189:Retrospective Studies; D013126:Spinal Nerve Roots / Q000503:physiopathology / Q000601:surgery
Cervical spondylotic amyotrophy; Clinical outcome; Drop finger; Surgical treatment