Distal anterior interosseous nerve in the recurrent motor branch graft for reconstruction of a median nerve neuroma-in-continuity

Median nerves with neuromas-in-continuity are preferably managed by the identification and preservation of the functioning motor fascicles proximal and distal to the neuroma. The non-functioning, painful sensory fibers are divided proximally and distally and are reconstructed with nerve grafts. In cases where the proximal motor fascicle may not be safely and effectively isolated because of scarring or previous surgical intervention, the distal anterior interosseous nerve (dAIN) may be grafted to the recurrent motor branch of the median (RMB) nerve distal to the neuroma. The primarily motor fibers of the dAIN provide an expendable donor of adequate size and fascicle number to restore thenar muscle function.     

Denatured muscle grafts for nerve repair. An experimental model of nerve damage in leprosy

About 20% of patients with leprosy develop localised granulomatous lesions in peripheral nerves. We report experiments in guinea-pigs in which freeze-thawed autogenous muscle grafts were used for the treatment of such mycobacterial granulomas. Granulomas were induced in guinea-pig tibial nerves and the animals were left for 7 to 100 days in order to assess maximal damage. The local area of nerve damage was then excised and the gap filled with denatured muscle grafts. Clinical assessment after periods up to 150 days showed good sensory and motor recovery which correlated well with the histological findings. The muscle graft technique may be of value for the treatment of chronic nerve lesions in selected cases of leprosy.     

Root reconstruction for bladder reinnervation: an experimental study in rats

Nerve transfer (or nerve crossover) is a well established technique for achieving reinnervation of a valuable sensory or motor territory by reconnection using a functional nerve of lesser value. Patients with lower spinal cord lesions causing neurogenic bladder dysfunction could theoretically benefit from such an approach for return of useful micturition. Based on the known anatomical details of the spinal nerve, a new reconstructive method was created to provide intradural ventral root transfer for pure motor-to-motor reinnervation and extradural postganglionic spinal nerve transfer for pure sensory-to-sensory reinnervation. Experimental studies in rats were performed, demonstrating the feasibility of this approach. A modified method is further suggested that would use nerve grafts for extradural approaches to pure motor and sensory transfers, without the need for extensive laminectomy and dura opening. This proposed approach is anticipated to minimize the associated morbidity and mortality with such spinal nerve reconstruction.     

Meaningful power grip recovery after salvage reconstruction of a median nerve avulsion injury with a pedicled vascularized ulnar nerve

In cases of median nerve injury alongside an unsalvageable ulnar nerve, a vascularized ulnar nerve graft to reconstruct the median nerve is a viable option. While restoration of median nerve sensation is consistently reported, recovery of significant motor function is less frequently observed. The authors report a case involving a previously healthy man who sustained upper arm segmental median and ulnar nerve injuries and, after failure of sural nerve grafts, was treated with a pedicled vascularized ulnar nerve graft to restore median nerve function. Long-term follow-up showed near full fist, with 12 kg of grip strength, key pinch with 1.5 kg of strength and protective sensation in the median nerve distribution. The present case demonstrates that pedicled ulnar vascularized nerve grafts can provide significant improvements to median nerve sensory and motor function in a heavily scarred environment.     

End-to-side neurorrhaphy of sensory nerves

One century passed before end-to-side neurorrhaphy was rediscovered, and now it finds more frequent use in clinical practice. Experimental studies have improved our understanding of the underlying mechanism and its potential. However, still discussed is whether reinnervation by end-to-side neurorrhaphy works as well in sensory nerves as in motor nerves. The digital nerves are sensory nerves and therefore an ideal model to investigate this question. Two cases of successful sensory reinnervation by end-to-side nerve suture are reported. We began to use end-to-side nerve repair clinically in 1995 and have used it for motor or sensory reinnervation in a total of 13 cases. In two patients primary nerve repair using end-to-side neurorrhaphy was performed in digital avulsion injuries. In one patient the avulsed ulnar nerve of the thumb was sutured end-to-side to the median nerve; in the other the ulnar digital nerve of the ring finger had been destroyed over a distance of 20 mm, and the distal stump was joined end-to-side to the radial nerve of the same finger. Sensory recovery was obtained in both patients. The static two-point discrimination was 3.0 mm, and dynamic two-point discrimination was 2-3 mm for the reinnervated finger compared to 2 mm for static and dynamic two-point discrimination in the adjacent "donor" finger. The sensation of the finger supplied by the "donor nerve" was not altered in relation to the corresponding contralateral finger site. Excellent sensory reinnervation is possible through an end-to-side nerve suture. Proximal avulsion, missing proximal nerve stumps, partial recovery, and prevention of nerve grafts are good indications for resensitization using end-to-side neurorrhaphy. No harm to the donor nerve is expected. Preference should be given to donor nerves that supply skin areas near to the anesthetic area.     

Brain plasticity and hand surgery: an overview

The hand is an extension of the brain, and the hand is projected and represented in large areas of the motor and sensory cortex. The brain is a complicated neural network which continuously remodels itself as a result of changes in sensory input. Such synaptic reorganizational changes may be activity-dependent, based on alterations in hand activity and tactile experience, or a result of deafferentiation such as nerve injury or amputation. Inferior recovery of functional sensibility following nerve repair, as well as phantom experiences in virtual, amputated limbs are phenomena reflecting profound cortical reorganizational changes. Surgical procedures on the hand are always accompanied by synaptic reorganizational changes in the brain cortex, and the outcome from many hand surgical procedures is to a large extent dependent on brain plasticity.     

Clinical results and thoughts on sensory nerve repair by autologous vein graft in emergency hand reconstruction

Lesions of the digital and other sensory nerves in the hand are common. Based on experimental studies on vein graft as a support for peripheral nerve regeneration, the Authors have been using a simple vein graft to bridge sensory nerve gaps when treating acute hand injuries. This is a retrospective study on the results of 22 sensory nerves repaired using vein grafts in cases in which primary suture was not feasible, in emergency hand reconstruction. Patients were informed that a secondary nerve graft could possibly be necessary in the future. Patients were reviewed by two independent observers at least one year after repair and evaluated using the Highest scale as modified by MacKinnon & Dellon. Evaluation chart included influence of repair on rehabilitation program and presence of painful neuromas and scars as well as patient satisfaction. Results were classified according to Sakellarides and 20/22 were classified as very good or good. Cases classified as poor were satisfied and no secondary nerve grafting has been carried out. Rehabilitation of the associated lesions (tendon lacerations or bone and soft tissue damage) was not influenced by the nerve repair and no painful neuroma was reported in the series. In conclusion, since the literature shows unsatisfactory results in repair of digital nerves with nerve grafts, since it's been demonstrated that an unrepaired sensory nerve leads to painful scar and painful neuroma and since we are reluctant to use nerve grafts in emergency procedures, we recommend this simple method because it is easy, low-cost and effective.     

Radial sensory neurotization of the thumb and index finger for prehension after proximal median and ulnar nerve injuries

Proximal median nerve injuries are functionally disabling, secondary to both motor and sensory deficits. Reestablishment of sensation relies on slow axonal regeneration originating from the site of injury after either primary nerve repair or the use of autogenous nerve grafts. This regeneration can take 2 or more years to restore sensation to the hand, depending on injury location. Distal sensory nerve transfers shorten the recovery time by decreasing the required regeneration distance. The authors present two case reports of patients with proximal median nerve injury, who underwent radial sensory nerve transfers to the ulnar digital nerve of the thumb and the radial digital nerve of the index finger. Protective sensation returned to the index and thumb fingertips at 3 months. By 6 months, both patients attained sufficient sensation to permit active lateral key pinch. At 9 months, each patient had moving sensation; and by 14 months, each patient attained proper localization. Successful digital nerve transfers of the dorsal radial sensory nerves in patients with high proximal median nerve injuries return sensation faster than traditional median nerve repairs. Use of this technique will significantly reduce the insensate time in patients with this unfortunate injury.     

A technique for the treatment of neuroma in-continuity.

A surgical technique for the management of a neuroma in-continuity, in which motor function is preserved and sensory function is reconstructed with nerve grafting, is presented. Tedious and potentially damaging dissection within the neuroma in-continuity is avoided. The functioning motor fascicles are identified proximal and distal to the injury site with electrical nerve stimulation eliciting muscle contraction. These motor fascicles are preserved. The electrically silent and nonfunctioning sensory fascicles are divided proximal and distal to the neuroma and reconstructed with autogenous nerve grafts. These nerve grafts bypass the functioning motor portion of the neuroma in-continuity.     

Surgical management of nerve injuries of the upper extremity in children: a 15-year survey

In a 15-year retrospective study, the results of 37 surgically treated nerve lesions of the upper extremity in 33 children were reviewed after a mean follow-up of 2 years. Children ranged in age from 4 to 15 years. There were 19 ulnar, 12 median, and 6 radial nerve injuries. Discontinuity of the nerve trunk was found in 23 patients operated by interfascicular grafting (18 patients) or epineural suture (5 patients). The other 14 lesions were treated by decompressive external neurolysis. Useful sensory function (S4-S3) assessed at the autonomous zone was restored in 31 patients (84%). Satisfactory motor recovery was achieved in 25 patients (67%). Independent of the type of lesion, the median nerve showed the best ability to regain complete motor and sensory function. In lesions with continuity of the nerve trunk, those affecting the radial nerve had a worse prognosis regarding motor function recovery. Unfavorable prognosis was mainly related to a time interval of more than 1 year between nerve damage and surgery.     

Secondary repair of ulnar nerve injury: 44 cases followed for 2 years

A series of 44 patients with complete section of the ulnar nerve was reviewed on average 2 years after secondary repair. The procedures applied were fascicular grafting in 33 cases, epineural suture in 7, and fascicular suture in 4. Useful ulnar motor function was restored in 22 cases of fascicular grafting, in all 4 of fascicular suture and in 3 of epineural suture. Sensibility recovered in 23 patients operated on by fascicular grafts and in 10 of 11 treated by epineural or fascicular suture. Cases with unsatisfactory results had other associated severe lesions, i.e., median nerve section, vascular damage or tendon injuries. Early repair of clean-cut nerve sections by fascicular or epineural suture gives a good chance for recovery. Grafting should be performed within 3 months and no later than 1 year after the injury.     

Secondary repair of ulnar nerve injury. 44 cases followed for 2 years

A series of 44 patients with complete section of the ulnar nerve was reviewed on average 2 years after secondary repair. The procedures applied were fascicular grafting in 33 cases, epineural suture in 7, and suture in 4. Useful ulnar motor function was restored in 22 cases of fascicular grafting, in all 4 of fascicular suture and in 3 of epineural suture. Sensibility recovered in 23 patients operated on by fascicular grafts and in 10 of 11 treated by epineural or fascicular suture. Cases with unsatisfactory results had other associated severe lesions, i.e., median nerve section, vascular damage or tendon injuries. Early repair of clean-cut nerve sections by fascicular or epineural suture gives a good chance for recovery. Grafting should be performed within 3 months and no later than 1 year after the injury.     

Restoration of sensation over the contact surfaces of the thumb-index pinch grip using the terminal branches of the superficial branch of the radial nerve

In huge median nerve losses and in some brachial plexus lesions, absence of sensation over the pulps of the index finger and the thumb preclude their use without visual control. Currently, end-to-side anastomosis is a new option available (when the ulnar nerve is intact) but we have reviewed the results of 7 cases of nerve anastomosis between the sensory branches of the radial nerve and the collateral nerves of the thumb (ulnar) and index finger (radial). Palmar translocation of the donor nerve, as classically performed, was used in two cases and the technique was subsequently modified to provide a better nerve suture by dorsal transfer of the collateral nerves of the thumb and index. Two sequellae of brachial plexus lesions and 5 cases of extensive defects of the median nerve were reviewed at a mean follow up of 5 years. With the classical technique the two point discrimination was 15 mm in one case and more in the other; with the modified technique, 4 patients achieved a thumb discriminaTion of 9 mm, 12 mm (2 cases) and 13 mm.     

Results of reinnervation of the biceps and brachialis muscles with a double fascicular transfer for elbow flexion

PURPOSE: To report the results of a surgical technique of nerve transfer to reinnervate the brachialis muscle and the biceps muscle to restore elbow flexion after brachial plexus injury. METHODS: Retrospective review was performed on 6 patients who had direct nerve transfer of a single expendable motor fascicle from both the ulnar and median nerves directly to the biceps and brachialis branches of the musculocutaneous nerve. Assessment included degree of recovery of elbow flexion and ulnar and median nerve function including pinch and grip strengths. RESULTS: Clinical evidence of reinnervation was noted at a mean of 5.5 months (SD, 1 mo; range, 3.5-7 mo) after surgery and the mean follow-up period was 20.5 months (SD, 11.2 mo, range, 13-43 mo). Mean recovery of elbow flexion was Medical Research Council grade 4+. Postoperative pinch and grip strengths were unchanged or better in all patients. No motor or sensory deficits related to the ulnar or median nerves were noted and all patients maintained good hand function. No patients required additional procedures to further improve elbow flexion strength. CONCLUSIONS: Transfer of expendable motor fascicles from the ulnar and median nerves successfully can reinnervate the biceps and brachialis muscles for strong elbow flexion. The reinnervation of the brachialis muscle, the primary elbow flexor, as well as the biceps muscle provides an additional biomechanical advantage that accounts for the excellent elbow flexion strength obtained using this technique. Direct coaptation of the nerve fascicles was performed without the need for nerve grafts and there was no functional or sensory donor morbidity.     

Lipofibroma of the median nerve.

Tumors arising within the median nerve in the region of the distal forearm, wrist, and palm are rare and their exact pathological nature has not been well clarified. One case is reported in a 47-year-old woman, in whom a mass of 3 years' duration was located in the thenar eminence of the right hand without causing any sensory or motor deficit. The tumor was surgically excised, and the continuity of the nerve branches was preserved. The diagnosis of lipofibroma of the median nerve is recommended for this entity. Other pathological lesions of the median nerve are mentioned.     

Reconstruction of high ulnar nerve lesions by distal double median to ulnar nerve transfer

Ulnar nerve lesions around the elbow often carry an unfavorable prognosis due to insufficient sensory and intrinsic muscle recovery. We present a series of 7 cases in which restoration of ulnar innervated intrinsic muscles of the hand and of skin sensibility was achieved. This was accomplished by a distal connection of the anterior interosseous nerve and the superficial sensory palmar branch of the median nerve to the motor and sensory components of the ulnar nerve at Guyon's canal. The length of the follow-up period ranged from 1 to 3.5 years. Results were graded by the Highet-Zachary scale. Good motor and sensory recovery was obtained in 6 cases; only return of protective sensation occurred in the remaining case.     

Long-term results of transplantations to repair median, ulnar, and radial nerve lesions by a microsurgical interfascicular autogenous cable graft technique

A comprehensive analysis of 187 patients (78 median, 86 ulnar, and 23 radial nerve lesions) treated by an interfascicular autogenous nerve grafting technique is presented. After a follow-up of at least 18 months good motor recovery was achieved in 72% of median nerve lesions, 77% of ulnar nerve lesions, and 57% of radial nerve lesions. Good functional sensory recovery was found in 36% of median, 45% of ulnar, and 48% of radial nerve lesions. It appears by multivariate analysis that the results obtained generally were better in younger patients, in patients with a shorter preoperative delay, and in cases with a shorter transplant.     

Selectivity of distal reinnervation of regenerating mixed motor and sensory nerve fibres across muscle grafts in rats

This study investigated target specificity during axonal regeneration of a mixed motor and sensory nerve towards respective targets. The femoral nerves in rats were divided and allowed to grow across a 6 mm gap interposed with frozen and thawed muscle grafts towards their distal motor and sensory nerve stumps. Fourteen weeks later the number of motoneurons projecting axons into the motor and sensory branches were determined by retrograde axonal tracing using horse-radish peroxidase. There were significantly higher numbers of motoneurons (p = 0.0034) projecting into the motor nerve than the sensory nerve. Efferent axons of a mixed nerve selectivity grew into motor branches when allowed to regenerate across a 6 mm gap interposed with muscle grafts. It is possible that a deliberately created 'structured gap' during repair of mixed nerves could improve axonal matching by allowing expression of neurotropism.     

The anatomy of the distal ulnar tunnel

The distal ulnar tunnel is a region of the wrist 4-4.5 cm in length in which the ulnar nerve is particularly vulnerable to external compression. The relation of the internal topography of the nerve to the structures comprising the tunnel provides a basis for dividing the tunnel into three zones. Zone 1 is that portion of the tunnel proximal to the bifurcation of the ulnar nerve. Zone 2 encompasses the deep motor branch of the nerve, and Zone 3 surrounds the superficial branch. A review of the literature of ulnar nerve compression lesions confirmed expectations based on the regional anatomy. Zone 1 lesions included all (39) cases of combined motor and sensory deficits, one case of pure motor paralysis, and seven cases of sensory deficits. All Zone 2 lesions (36 cases) resulted in paralysis of the intrinsic muscles. Whether or not the hypothenar muscles were affected was dependent upon the location of the lesions within Zone 2. Zone 3 lesions caused sensory deficits only. Combined motor and sensory loss was most often caused by compression from deep to the nerve, while pure sensory deficits were a result of compression lesions lying superficial to the nerve.     

Partial nerve injuries in the upper extremity

The level of injury of a peripheral nerve is a critical factor that has a great impact on the result of the repair. At the level of the wrist, the median and ulnar nerves have pure motor and sensory fascicular groups. Proximal to the wrist, the motor fascicular groups combine with sensory fascicles and become mixed nerves. Mapping the fascicular orientation with electrical stimulation is indicated for injuries located from the wrist to the distal third of the forearm. Successful application of this technique depends on the level of injury, anesthetic technique, and careful patient selection. Children and patients with other serious coexisting injuries are not candidates for this technique. The depth of anesthesia must provide adequate analgesia while allowing the patient to communicate and cooperate with the surgeon during the procedure. There are few reports in the literature about repair of partially injured nerves in the upper extremities and the comparison of functional outcomes with or without the use of nerve grafts is not easy. Even under ideal operative conditions and with ideal indications, the outcomes are not always satisfactory. Hurst et al reported very good results using end-to-end repair of fascicular groups in their series. Using the rating system of the British Medical Research Council, they reported motor values of 4.0 (normal 5.0), and sensory values of 3.8 (normal 4.0). Kato et al reported very good results in their series of 51 cases with group fascicular end-to-end suture using orientation with electrical stimulation. In this series, there were five patients with partial nerve laceration and end-to-end coaptation of the fascicular groups provided very satisfactory outcome. End-to-end repair of the fascicular groups seems to provide better results than repair of the nerve using nerve grafts. It is desired, however, that the nerve gap be less than 2 cm for the application of end-to-end repair of the nerve.