Reconstruction of Monteggia-like proximal ulna fractures using different fixation devices: A biomechanical study.

BACKGROUND: Comminuted proximal ulna fractures are rare and reconstruction of these fractures is discussed controversially. The aim of this study was to test three currently available plate devices in a standardized comminuted four-part fracture model created in proximal ulna sawbones. MATERIAL AND METHODS: A standardized four-part fracture of the proximal ulna was created in 80 sawbones. Reconstruction was performed by five experienced test surgeons according to a standardized reconstruction protocol. Each surgeon reconstructed 4 fractures with a 3.5mm eight-hole reconstruction plate, 4 fractures with seven-hole third-tubular double plates and 4 fractures with a 3.5mm anatomical seven-hole locked angle proximal ulna plate. 4 more fractures were reconstructed with simple K-wires as a reference construct for further experiments. Outcome measurements were time for reconstruction, quality of reconstruction and stability of the reconstruction. Stability testing was done in 90° and 30° flexion of the elbow. Testing in 30° flexion was done to test the anteroposterior stability regarding the fixed coronoid process. RESULTS: Time for reconstruction was significantly less for K-wire fixation than for the plate devices. Time for reconstruction plating and locked angle plating was significantly lower than for double plating (p<0.005). Quality of reduction did not differ between the three plate systems (p<0.05). K-wire fixation showed the best quality of reduction (p<0.005). In 90° of elbow flexion the anatomic locked angle olecranon plate showed a significantly higher stability compared to the other devices. Furthermore the tubular double plating was significantly more stable than reconstruction plating or K-wire fixation (p<0.05). In anteroposterior loading at 30°, the stability did not differ between the 4 different fixation techniques (p>0.05). For all devices the testing in 30° flexion showed a significantly higher rigidity compared to 90° flexion. CONCLUSION: The locked angle plate system showed the highest stability in 90° of elbow flexion. Each implant was more stable in 30° flexion than in 90° flexion. Testing of the anterior stability of the elbow did not show any differences between the different implants. Because of the superior stability of this device, we conclude that locked angle plating should be preferred for reconstruction of monteggia like complex proximal ulna fractures.

[Percutaneous needle aponeurotomy for Dupuytren's disease]. / Die perkutane Nadelaponeurotomie der Dupuytren-Kontraktur.

OBJECTIVE: Percutaneous transverse aponeurotomy of the cord by using a hypodermic needle as a scalpel blade in order to improve function of the hand. INDICATIONS: Symptomatic flexion contracture with positive table top test caused by a single, palpable cord within the palm (primarily Tubiana stages I and II). CONTRAINDICATIONS: Multiple, infiltrating or broad-based cords within the palm; irritated skin conditions; exclusive digital cord localization; recurrence after aponeurectomy; previous surgical intervention at the site of interest, digital nerve lesions; lack of patient compliance. SURGICAL TECHNIQUE: Pinpoint surface anesthesia is obtained by injecting each portal area subdermally with 0.1 ml of local anesthetic. These applications start from distally to proximally within the palm while the most distal injection site is located proximal to the distal palm crease. Then the needle tip is introduced perpendicular to the cord. Sawing movements through the cord are performed transversely. While passively extending the contracted finger, the cord is held under tension which guarantees safe cutting. Patients are encouraged to report immediate pain sensation or numbness in order to prevent injuries to neurovascular structures and active finger flexion excludes tendon lesions during the procedure. Introducing the needle tip may be performed at several sites along the cord, if necessary, from distal to proximal at least 5 mm apart with prior pinpoint surface anesthesia. Finally, cautious passive stretching may be done after each release. POSTOPERATIVE MANAGEMENT: Bandaging allowing immediate motion; application of a hand-based extension splint-glove during the night for 3-6 months. RESULTS: Recurrence rate was 53% in 15 retrospectively examined patients after a mean interval of 40 months postoperatively.

Operative treatment and outcome of unstable distal radial fractures using a palmar T-miniplate at a non-specialized institution.

Treatment options for displaced distal radial fractures are still a controversial topic of discussion. Although good results for the palmar plating of high-volume centers have been published, evidence of its successful use in smaller institutions is still lacking. We report the clinical and radiological results of the treatment for 84 distal radial fractures with a single 2.4-mm T-miniplate in an institution performing <30 procedures per year. According to the AO classification system, there were 30 A, 5 B, and 49 C fractures with a patients mean age of 64 years. After a minimum of 12-month follow-up, we found very good and good results according to the Gardland and Sarmiento scores and a DASH of 5.6. Only five patients were classified as having a moderate outcome. A remaining intra-articular step-off of more than 1 mm was seen in 15 patients. In a comparison of grip strength between the injured and uninjured hands, we saw a difference of 6.8 % less on the injured side. We saw two instances of tendon rupture and one of tendon irritation due to prominent dorsal screws and necessitating revision surgery. Flexor tendon irritation was noted in one patient, requiring a second operation. Modern treatment for distal radial fractures can be performed successfully and with good clinical outcome in smaller institutions. Based on the high and increasing incidence of distal radial fractures, there is no need to transfer these patients into high-volume centers. Level of evidence Case study, Level IV.

[Anatomic relationship between the pronator quadratus and brachioradialis muscle insertion: implications for repair of the muscle after volar plate fixation of distal radius fractures]. / Die topografische Beziehung des M. pronator quadratus zum Ansatz des M. brachioradialis--Implikationen für die Refixation nach palmarer Plattenosteosynthese distaler Radiusfrakturen.

BACKGROUND: In open reduction and volar plate fixation of distal radius fractures, the pronator quadratus (PQ) muscle is usually detached at the radial edge of the distal radius. Repair of the muscle is reasonable for coverage of the plate and to maintain normal pronation of the forearm. However, repair of the muscle is not always satisfactory. In this study, the topographic relationship of both the PQ and the brachioradialis muscle (BR) insertions are investigated with regard to optimising the repair of the PQ in open reduction and volar plate fixation of distal radius fractures. MATERIALS AND METHODS: Twelve forearm pairs fixed in formalin were examined. The muscular boundaries of the PQ and the insertion of the BR were dissected, photographs were taken and measured digitally. RESULTS: The average distance of the PQ insertion was 4.75 cm. Distally, a close topographic relationship exists between the insertions of both the PQ and BR. A fascial connection of both muscles was detected in all specimens. The average distance of the common insertion was 1.75 cm. After removal of the PQ fascia, 0.85 cm of common insertion remained. In 25 % a muscular connection between both the PQ and BR was detected after removal of the PQ fascia. CONCLUSION: Both the PQ and BR have a common connective tissue and partially a common muscular insertion. Detaching the PQ insertion with a part of the BR insertion in open reduction and volar plate fixation of distal radius fractures can presumably lead to a more stable repair of the PQ in contrast to a repair within the muscle.

Functional deficits and morphological changes in the neurogenic bladder match the severity of spinal cord compression.

UNLABELLED: Following spinal cord injury (SCI), loss of spinal and supraspinal control results in desynchronisation of detrusor vesicae (parasympathicus) and external urethral sphincter (sympathicus) activity. Despite recovery of lower urinary tract function being a high priority in patients with SCI, effective treatment options are unavailable largely because mechanisms are poorly understood. PURPOSE AND METHODS: We used a clinically relevant model of thoracic SCI compression injury in adult female Wistar rats and confirmed that lesion volumes following severe injuries were significantly greater compared to moderate injuries (p < 0.05). Between 1-9 weeks, we assessed recovery of bladder function as well as return of locomotor function using the Basso, Beattie and Bresnahan (BBB) score. Bladder morphometrics and overall intramural innervation patterns, as assessed with ß-III tubulin immunohistochemistry, were also examined. RESULTS: Despite variability, bladder function was significantly worse following severe compared to moderate compression injury (p < 0.05); furthermore, the degree of bladder and locomotor dysfunction were significantly correlated (r = 0.59; p < 0.05). In addition, at 9 weeks after SCI we saw significantly greater increases in bladder dry weight (p < 0.05) and wall thickness following severe compared to moderate injury as well as increases in intramural axon density (moderate: 3× normal values; severe 5×; both p < 0.05) that also correlated with injury severity (r = 0.89). CONCLUSION: The moderate and severe compression models show consistent and correlated deficits in bladder and locomotor function, as well as in gross anatomical and histopathological changes. Increased intramural innervation may contribute to neurogenic detrusor overactivity and suggests the use of therapeutic agents which block visceromotoric efferents.

Compartments of the foot: topographic anatomy.

Recent publications have renewed the debate regarding the number of foot compartments. There is also no consensus regarding allocation of individual muscles and communication between compartments. The current study examines the anatomic topography of the foot compartments anew using 32 injections of epoxy-resin and subsequent sheet plastination in 12 cadaveric foot specimens. Six compartments were identified: dorsal, medial, lateral, superficial central, deep forefoot, and deep hindfoot compartments. Communication was evident between the deep hindfoot compartment and the superficial central and deep central forefoot compartments. In the hindfoot, the neurovascular bundles were located in separate tissue sheaths between the central hindfoot compartment and the medial compartment. In the forefoot, the medial and lateral bundles entered the deep central forefoot compartment. The deep central hindfoot compartment housed the quadratus plantae muscle, and after calcaneus fracture could develop an isolated compartment syndrome.

Tibiofibular screw fixation for syndesmotic ruptures: a biomechanical analysis.

The mechanisms of injuries to the tibiofibular syndesmosis include isolated rupture and rupture in combination with ankle fractures. Current concepts of surgical treatment are fixation using bioabsorbable screws, syndesmotic stapling, syndesmotic hooks, and the widely used screw fixation. Postoperative care utilises passive motion of the ankle joint either with or without axial weight-bearing. The aim of our investigation was to quantify the motion of the mortise during axial load. Therefore, photoelastic tests, on the one hand, and biomechanical tests of cadaveric specimens, on the other, using axial loads of up to 2,000 N were used. Our photoelastic investigations showed force distribution through the screw into the cranial and caudal parts of the distal fibula. Biomechanical testing showed a progressive dehiscence in both ruptured and fixated specimens up to 2.89 (ruptured) and 2.42 mm (despite screw). Our findings strongly suggest a concept of partial weight-bearing at most to support regeneration of scar tissue and to prevent the appearance of instability in the ankle joint.

[Appearance of complex regional pain syndrome after intramedullary nailing of a clavicle fracture]. / Auftreten eines Complex-regional-pain-Syndroms nach intramedullärer Nagelung einer Klavikulaschaftfraktur.

After operative correction of a clavicle fracture using an elastic stable intramedullary nail the patient presented signs of delayed fracture healing after 2 months. During the sixth postoperative month the 28-year-old obviously pain-ridden female patient showed dystonia of the shoulder girdle and allodynia surrounding the operation field. Upon these findings, we decided - as a result of the complex regional pain syndrome that had not been previously described in this location - to treat the patient by administering bisphosphonates, multimodal analgetic therapy, physiotherapy and occupational therapy. Fourteen months after surgery, the patient showed no remaining symptoms, and the fracture had consolidated at that time.

Non-invasive stimulation of the vibrissal pad improves recovery of whisking function after simultaneous lesion of the facial and infraorbital nerves in rats.

We have recently shown that manual stimulation of target muscles promotes functional recovery after transection and surgical repair to pure motor nerves (facial: whisking and blink reflex; hypoglossal: tongue position). However, following facial nerve repair, manual stimulation is detrimental if sensory afferent input is eliminated by, e.g., infraorbital nerve extirpation. To further understand the interplay between sensory input and motor recovery, we performed simultaneous cut-and-suture lesions on both the facial and the infraorbital nerves and examined whether stimulation of the sensory afferents from the vibrissae by a forced use would improve motor recovery. The efficacy of 3 treatment paradigms was assessed: removal of the contralateral vibrissae to ensure a maximal use of the ipsilateral ones (vibrissal stimulation; Group 2), manual stimulation of the ipsilateral vibrissal muscles (Group 3), and vibrissal stimulation followed by manual stimulation (Group 4). Data were compared to controls which underwent surgery but did not receive any treatment (Group 1). Four months after surgery, all three treatments significantly improved the amplitude of vibrissal whisking to 30° versus 11° in the controls of Group 1. The three treatments also reduced the degree of polyneuronal innervation of target muscle fibers to 37% versus 58% in Group 1. These findings indicate that forced vibrissal use and manual stimulation, either alone or sequentially, reduce target muscle polyinnervation and improve recovery of whisking function when both the sensory and the motor components of the trigemino-facial system regenerate.

Poor functional recovery and muscle polyinnervation after facial nerve injury in fibroblast growth factor-2-/- mice can be improved by manual stimulation of denervated vibrissal muscles.

Functional recovery following facial nerve injury is poor. Adjacent neuromuscular junctions (NMJs) are "bridged" by terminal Schwann cells and numerous regenerating axonal sprouts. We have recently shown that manual stimulation (MS) restores whisking function and reduces polyinnervation of NMJs. Furthermore, MS requires both insulin-like growth factor-1 (IGF-1) and brain-derived neurotrophic factor (BDNF). Here, we investigated whether fibroblast growth factor-2 (FGF-2) was also required for the beneficial effects of MS. Following transection and suture of the facial nerve (facial-facial anastomisis, FFA) in homozygous mice lacking FGF-2 (FGF-2(-/-)), vibrissal motor performance and the percentage of poly-innervated NMJ were quantified. In intact FGF-2(-/-) mice and their wildtype (WT) counterparts, there were no differences in amplitude of vibrissal whisking (about 50°) or in the percentage of polyinnervated NMJ (0%). After 2 months FFA and handling alone (i.e. no MS), the amplitude of vibrissal whisking in WT-mice decreased to 22±3°. In the FGF-2(-/-) mice, the amplitude was reduced further to 15±4°, that is, function was significantly poorer. Functional deficits were mirrored by increased polyinnervation of NMJ in WT mice (40.33±2.16%) with polyinnervation being increased further in FGF-2(-/-) mice (50.33±4.33%). However, regardless of the genotype, MS increased vibrissal whisking amplitude (WT: 33.9°±7.7; FGF-2(-/-): 33.4°±8.1) and concomitantly reduced polyinnervation (WT: 33.9%±7.7; FGF-2(-/-): 33.4%±8.1) to a similar extent. We conclude that, whereas lack of FGF-2 leads to poor functional recovery and target reinnervation, MS can nevertheless confer some functional benefit in its absence.

[Revision arthroplasty of the elbow]. / Revisionsendoprothetik des ellenbogens.

Total elbow arthroplasty (TEA) is gaining in popularity. An elbow prosthesis is nowadays no longer regarded as a salvage procedure for low demand patients but is increasingly used in younger, active patients with higher demands. In elderly patients TEA is more and more accepted as a primary treatment method for osteoporotic complex distal humerus fractures. Nevertheless, TEA is technically demanding and associated with a higher complication and revision rate compared to e.g. hip prostheses. Increasing implantation rates in a juvenescent population will lead to a considerable increase in revision rates. Most common causes are aseptic and septic loosening as well as implant failure and instability. Cemented semi-constrained prostheses are mostly used for revision elbow arthroplasty. This article deals with the causes of revision elbow arthroplasty and describes the operative technique of revision of total elbow arthroplasty.

Recovery of whisking function after manual stimulation of denervated vibrissal muscles requires brain-derived neurotrophic factor and its receptor tyrosine kinase B.

Functional recovery following facial nerve injury is poor. Neuromuscular junctions (NMJs) are "bridged" by terminal Schwann cells and numerous regenerating axonal sprouts. We have shown that this poly-innervation of NMJs can be reduced by manual stimulation (MS) with restoration of whisking function. In addition, we have recently reported that insulin-like growth factor-1 (IGF-1) is required to mediate the beneficial effects of MS. Here we extend our findings to brain derived neurotrophic factor (BDNF). We then examined the effect of MS after facial-facial anastomosis (FFA) in heterozygous mice deficient in BDNF (BDNF(+/-)) or in its receptor TrkB (TrkB(+/-)). We quantified vibrissal motor performance and the percentage of NMJ bridged by S100-positive terminal Schwann cells. In intact BDNF(+/-) or TrkB(+/-) mice and their wild type (WT) littermates, there were no differences in vibrissal whisking nor in the percentage of bridged NMJ (0% in each genotype). After FFA and handling alone (i.e. no MS) in WT animals, vibrissal whisking amplitude was reduced (60% lower than intact) and the percentage of bridged NMJ increased (27% more than intact). MS improved both the amplitude of vibrissal whisking (not significantly different from intact) and the percentage of bridged NMJ (11% more than intact). After FFA and handling in BDNF(+/-) or TrkB(+/-) mice, whisking amplitude was again reduced (53% and 60% lower than intact) and proportion of bridged NMJ increased (24% and 29% more than intact). However, MS failed to improve outcome in both heterozygous strains (whisking amplitude 55% and 58% lower than intact; proportion of bridged NMJ 27% and 18% more than intact). We conclude that BDNF and TRkB are required to mediate the effects of MS on target muscle reinnervation and recovery of whisking function.

Recovery of whisking function promoted by manual stimulation of the vibrissal muscles after facial nerve injury requires insulin-like growth factor 1 (IGF-1).

Recently, we showed that manual stimulation (MS) of denervated vibrissal muscles enhanced functional recovery following facial nerve cut and suture (FFA) by reducing poly-innervation at the neuro-muscular junctions (NMJ). Although the cellular correlates of poly-innervation are established, with terminal Schwann cells (TSC) processes attracting axon sprouts to "bridge" adjacent NMJ, molecular correlates are poorly understood. Since quantitative RT-PCR revealed a rapid increase of IGF-1 mRNA in denervated muscles, we examined the effect of daily MS for 2 months after FFA in IGF-1(+/-) heterozygous mice; controls were wild-type (WT) littermates including intact animals. We quantified vibrissal motor performance and the percentage of NMJ bridged by S100-positive TSC. There were no differences between intact WT and IGF-1(+/-) mice for vibrissal whisking amplitude (48 degrees and 49 degrees ) or the percentage of bridged NMJ (0%). After FFA and handling alone (i.e. no MS) in WT animals, vibrissal whisking amplitude was reduced (60% lower than intact) and the percentage of bridged NMJ increased (42% more than intact). MS improved both the amplitude of vibrissal whisking (not significantly different from intact) and the percentage of bridged NMJ (12% more than intact). After FFA and handling in IGF-1(+/-) mice, the pattern was similar (whisking amplitude 57% lower than intact; proportion of bridged NMJ 42% more than intact). However, MS did not improve outcome (whisking amplitude 47% lower than intact; proportion of bridged NMJ 40% more than intact). We conclude that IGF-I is required to mediate the effects of MS on target muscle reinnervation and recovery of whisking function.

[Successive ruptures of patellar and Achilles tendons. Anabolic steroids in competitive sports]. / Mehrzeitige Rupturen von Patellar- und Achillessehnen. Anabole Steroide im Leistungssport.

Derivatives of testosterone or of 19-nor-testosterone are used as anabolics for the purpose of improving performance although the effect of anabolics is known still to be under discussion. The use of anabolic steroids continues among competitive athletes despite increased controls and increasingly frequent dramatic incidents connected with them. Whereas metabolic dysfunction during anabolic use is well documented, ruptures of the large tendons are rarely reported. Within 18 months, a 29-year-old professional footballer needed surgery for rupture of the patellar tendon and of both Achilles tendons. Carefully directed questioning elicited confirmation that he had taken different anabolic steroids regularly for 3 years with the intention of improving his strength. After each operation anabolic steroids were taken again at a high dosage during early convalescence and training. Minimally invasive surgery and open suturing techniques led to complete union of the Achilles tendons in good time. Training and anabolic use (metenolon 300 mg per week) started early after suturing of the patellar tendon including bone tunnels culminated in histologically confirmed rerupture after 8 weeks. After a ligament reconstruction with a semitendinosus tendon graft with subsequent infection, the tendon and reserve traction apparatus were lost. Repeated warnings of impaired healing if anabolic use was continued had been given without success. In view of the high number of unrecorded cases in competitive and athletic sports, we can assume that the use of anabolic steroids is also of quantitative relevance in the operative treatment of tendon ruptures.

Manual stimulation of forearm muscles does not improve recovery of motor function after injury to a mixed peripheral nerve.

Transection and re-anastomosis of the purely motor facial nerve leads to poor functional recovery. However, we have recently shown in rat that manual stimulation (MS) of denervated vibrissal muscles reduces the number of polyinnervated motor endplates and promotes full recovery of whisking. Here, we examined whether MS of denervated rat forearm muscles would also improve recovery following transection and suture of the mixed (sensory and motor) median nerve (median-median anastomosis, MMA). Following MMA of the right median nerve, animals received no postoperative treatment, daily MS of the forearm muscles or handling only. An almost identical level of functional recovery, measured by the force of grip in grams, was reached in all animals by the sixth postoperative week and maintained till 3 months following surgery regardless of the postoperative treatment. Also, we found no differences among the groups in the degree of axonal sprouting, the extent of motor endplate polyinnervation and in the soma size of regenerated motoneurons. Taken together, we show that while MS is beneficial following motor nerve injury, combined strategies will be required for functional recovery following mixed nerve injury.

Evaluation of muscle re-innervation employing pre- and post-axotomy injections of fluorescent retrograde tracers.

In experimental studies on peripheral nerve repair, the possibility to objectively compare original and post-operative innervation is of decisive importance for the selection of the proper nerve-reconstruction strategy. Herewith we report serious drawbacks encountered with the standard method of pre- and post-operative intramuscular injections of widely used retrograde neuronal tracers. Labeling of rat facial motoneurons by injection of Fast-Blue (FB; Group 1), Dil (Group 2), or Fluoro-Gold (FG; Group 3) into the whisker pad muscles was followed by transection and suture of the facial nerve. Two months later, the same rats received Dil (Group 1), FG (Group 2), and FB (Group 3) injections with the same parameters as the pre-operative injections. By quantitative evaluation of single- and double-retrogradely labeled perikarya of facial motoneurons, we tried to estimate the accuracy of re-innervation. Observations through a "UV-filter" (for FB-labeled perikarya) and a "rhodamine-filter" (for Dil-labeled perikarya) in Group 1 revealed an unexpected axotomy-triggered leakage of FB which compromised the counts. After pre-operative Dil labeling, nerve suture, and post-operative FG labeling (Group 2), Dil created an extracellular deposit in the whisker pad. Thus, the uptake of pre-operative tracer by sprouts of re-growing axons compromised counts of retrogradely labeled motoneurons. Employing the "UV-filter" in Group 3 (FG-, FB-, FG+FB-labeled perikarya), the emission of FB obscured that of FG and also compromised cell counts. The use of filter sets constructed ad hoc for detection of FG and FB rendered possible an objective comparison.

Superior muscle reinnervation after autologous nerve graft or poly-L-lactide-epsilon-caprolactone (PLC) tube implantation in comparison to silicone tube repair.

Recovery after peripheral nerve injury depends not only on the amount of reinnervation, but also on its accuracy. The rat sciatic nerve was subjected to an 8 mm long gap lesion repaired either by autograft (AG, n = 6) or tubulization with impermeable silicone tube (SIL, n = 6) or permeable tube of poly-L-lactide-epsilon-caprolactone (PLC, n = 8). Recordings of the compound muscle action potential (CMAP) from gastrocnemius (mGC), tibialis anterior (mTA) and plantar (mPL) muscles were performed 90 days after injury to assess the amount of muscle reinnervation. The CMAP amplitude achieved in mGC, mTA and mPL was similar in after nerve autograft (39%, 42%, 22% of control values) and PLC tube implantation (37%, 36%, 24%) but lower with SIL tube (29%, 30%, 14%). The nerve fascicles projecting into each of these muscles were then transected and retrograde tracers (Fluoro Gold, Fast Blue, DiI) were applied to quantify the percentage of motoneurons with single or multiple branches to different targets. The total number of labeled motoneurons for the three muscles did not differ in autografted rats (1186 +/- 56; mean +/- SEM) with respect to controls (1238 +/- 82), but was reduced with PLC tube (802 +/- 101) and SIL tube (935 +/- 213). The percentage of neurons with multiple projections was lower after autograft and PLC tube (6%) than with SIL tube (10%). Considering the higher CMAP amplitude and lower number of neurons with multiple projections, PLC nerve conduits seem superior to SIL tubes and a suitable alternative to autografts for the repair of long gaps.

Contralateral trigeminal nerve lesion reduces polyneuronal muscle innervation after facial nerve repair in rats.

Functional recovery after facial nerve surgery is poor. Axotomized motoneurons (hyperexcitable upon intracellular current injections, but unable to discharge upon afferent stimulation) outgrow supernumerary branches which are misrouted towards improper muscles. We hypothesized that alterations in the trigeminal input to axotomized electrophysiologically silent facial motoneurons might improve specificity of reinnervation. To test this we compared, in the rat, behavioural, electrophysiological, and morphological parameters after transection and suture of the buccal facial nerve (buccal-buccal anastomosis, BBA) with those after BBA plus excision of the ipsi- or contralateral infraorbital nerve (ION). After BBA, the mystacial vibrissae dropped and remained motionless until 18-21 days post operation (days PO). After BBA plus ipsilateral ION excision, there was no recovery of vibrissae whisking at all. Following BBA plus contralateral ION excision, full restoration of whisking occurred at 7-10 days PO. Electromyography of whiskerpad muscles showed normal waveform and amplitude was also most rapidly restored after BBA plus contralateral ION excision. Neuron counts after retrograde tracing showed that the intact buccal nerve contained axons of the superior (91%) and inferior (9%) buccolabial nerves. After BBA, the superior nerve comprised 56%, the inferior 21%, and 23% of the motoneurons projected within both nerves. After BBA plus ipsilateral ION excision, misdirection worsened and values changed to 48, 39 and 13%, respectively. After BBA plus contralateral ION excision, portions improved to 69, 23 and 8%. We conclude that, by reducing the redundant axon branching, lesion of contralateral ION provides the best conditions for recovery of vibrissae rhythmical whisking after reconstructive surgery on the facial nerve.