ObjectiveTo explore the feasibility of transposition of the proximal motor branches from tibial nerve (TN) as direct donors to suture the deep peroneal nerve (DPN) so as to provide a basis for surgical treatment of high fibular nerve injury. MethodsNineteen lower limb specimens were selected from 3 donors who experienced high-level amputation (2 left limbs and 1 right limb) and 8 fresh frozen cadavers (8 left limbs and 8 right limbs). The length and diameter of the three motor branches from TN (soleus, medial gastrocnemius, and lateral gastrocnemius) and the distance from the initial points to the branch point of the common peroneal nerve (CPN), as well as the length and diameter of the noninvasive separated bundles of DPN, then the feasibility of tensionless suturing between the donor nerves and the DPN bundle was evaluated. At last, part of the nerve tissue was cut out for HE and Acetylcholine esterase staining observation and the nerve fiber count. ResultsGross anatomic observation indicated the average distance from the initial points of the three donor nerves to the branch point of the CPN was (71.44±2.76) (medial gastrocnemius), (75.66±3.20) (lateral gastrocnemius), and (67.50±3.22) mm (soleus), respectively. The three donor nerves and the DPN bundles had a mean length of (31.09±2.01), (38.44±2.38), (59.18±2.72), and (66.44±2.85) mm and a mean diameter of (1.72±0.08), (1.88±0.08), (2.10±0.10), and (2.14±0.12) mm, respectively. The histological observation showed the above-mentioned four nerve bundles respectively had motor fiber number of 2 032±58, 2 186±24, 3 102±85, and 3 512±112. Soleus nerve had similar diameter and number of motor fibers to DPN bundles (P>0.05), but the diameter and number of motor fibers of the medial and lateral gastrocnemius were significantly less than those of DPN bundles (P<0.05). ConclusionAll of the three motor branches from TN at popliteal fossa can be used as direct donors to suture the DPN for treating high CPN injuries. The nerve to the soleus muscle should be the first choice.
ObjectiveTo investigate the regularity of myelin degeneration and regeneration and the difference of axonal density between tibial nerve and common peroneal nerve after sciatic nerve injury repair in rhesue monkey. MethodsNine adult rhesue monkeys (male or female, weighing 3.5-4.5 kg) were selected to establish the model of rat sciatic nerve transaction injury. The tibial nerve and common peroneal nerve of 5 mm in length were harvested at 5 mm from injury site as controls in 3 monkeys; the distal tibial nerve and common peroneal nerve were repaired with 9-0 suture immediately in the other 6 monkeys. And the gross observation and neural electrophysiological examination were performed at 3 and 8 weeks after repair respectively. Then, distal tibial nerve and common peroneal nerve at anastomotic site were harvested to observe the myelin sheath changes, and to calculate the number of axon counts and axonal density by staining with Luxol Fast Blue. ResultsAtrophy of the lower limb muscle and various degrees of plantar ulcer were observed. Gross observation showed nerve enlargement at anastomosis site, the peripheral connective tissue hyperplasia, and obvious adhesion. The compound muscle action potential (CMAP) of tibial nerve and common peroneal nerve could not be detected at 3 weeks; the CMAP amplitude of common peroneal nerve was less than that of the tibial nerve at 8 weeks. Different degrees of axonal degeneration was shown in the tibial nerve and common peroneal nerve, especially in the common peroneal nerve. The average axonal density of common peroneal nerve was lower than that of tibial nerve at 3 weeks (13.2% vs. 44.5%) and at 8 weeks (10.3% vs. 35.3%) after repair. ConclusionThe regeneration of tibial nerve is better and faster than that of common peroneal nerve, and gastrocnemius muscle CMAP recovers quicker, and amplitude is higher, which is the reason of better recovery of tibial nerve.