Transfer of the extensor digiti minimi and extensor carpi ulnaris branches of the posterior interosseous nerve to restore intrinsic hand function: case report and anatomic study

Bilateral Ulnar Nerve Injury in the Wrist: Comparison of First Webspace Muscle Reconstruction by Opponens Nerve Transfer in the Right Hand Versus Direct Ulnar Nerve Repair in the Left Hand

We report a case of a bilateral glass injury to the wrist with transection of flexor tendons and the ulnar nerve and artery in a 60-year-old male patient. Two days after his accident, we repaired all divided structures, and on the right hand, we added the transfer of the opponens motor branch to the deep terminal division of the ulnar nerve aimed at first dorsal interosseous and adductor pollicis muscle reinnervation. After surgery, the patient was followed over 24 months. Postoperative dynamometry of the hand, which included grasping, key-pinch, subterminal-key-pinch, pinch-to-zoom, and first dorsal interosseous muscle strength, indicated recovery only in the nerve transfer side.

Evaluation of functional recovery in the intrinsic and flexor muscles after nerve transfer for ulnar nerve lesion. A new measurement method: The Cha method

"Supercharge" end-to-side (SETS) nerve transfer for lesions of the proximal ulnar nerve is a recognized novel option, but improvement in motor function after surgery has not been properly evaluated. We therefore propose a modified method for quantitative evaluation of improvement in the intrinsic hand strength. We screened 216 patients with proximal ulnar nerve lesions who presented to our outpatient department from 2012 to 2020. Of these, 101 met our inclusion/exclusion criteria and were evaluated just before surgery. We used a novel method to measure finger abduction ("2nd-abd"), adduction ("5th-add"), and ring and little finger flexion strength ("4,5 grip"), and analyzed correlations with established pinch strength data. The male:female sex ratio was 86:15, and the ratio dominant to nondominant arm involvement was 68:33. All strength measurements were analyzed as percentage affected to contralateral normal side. On Pearson correlation analysis, the strength ratios for "4,5 grip", "2nd-abd", and "5th-add", but not "5 fingers (total) grip", showed significant positive correlation with key and oppositional pinch strength (all p < 0.001). Additionally, linear regression analysis showed identical results for each strength correlation with key/oppositional pinch, except for "5 fingers total) grip" (all, p < 0.001). SETS is a reasonable alternative for lesions of the proximal ulnar nerve. The measurement method we propose is feasible for specific assessment of intrinsic muscle strength, which improves after surgery. LEVEL OF EVIDENCE: Diagnostic, level IV.

Outcomes of anterior interosseous nerve transfer to restore intrinsic muscle function after high ulnar nerve injury

Traumatic high ulnar nerve injuries have historically resulted in long-term loss of hand function due to the long re-innervation distance to the intrinsic muscles. Transfer of the anterior interosseous nerve (AIN) to the deep motor branch of the ulnar nerve (MUN) is proving promising in these patients. The purpose of this study was to evaluate the outcomes and efficacy of this procedure in our series. Eligible high ulnar nerve injury patients who underwent AIN to MUN nerve transfer were evaluated with a mean follow-up of 17 months. Data including demographics, injury details, surgical procedures, and outcomes were collected. A review of the current literature was performed for comparison. Sixteen patients had AIN to MUN transfer, mean age of 39.4 years, and a median delay from injury to nerve transfer of 0.8 months. The injury site was above the elbow in 5 cases, at the elbow in 8 cases, and in the proximal forearm in 3 cases. The majority were sharp transection, with the remaining from blast injuries, traumatic traction, and one post-traumatic neuroma resection. Transfer was performed end-to-end in 7 cases, hemi end-to-end in 7 cases, and supercharged end-to-side in 2 cases. Five patients achieved intrinsic muscle recovery of MRC 4+ and thirteen gained MRC 3 or above. The AIN to MUN nerve transfer provides meaningful intrinsic recovery in the majority of traumatic high ulnar nerve injuries. This procedure should be routinely considered, however, warrants further research to validate the optimum technique.

Tendon transfer surgery for radial nerve palsy

Palliative tendon transfer is an integral part of radial nerve palsy treatment. It can be considered in the first weeks when the possibility of nerve repair by direct suture or nerve grafting is not feasible or reasonable. Mostly, it is discussed secondarily when it is too late for nerve surgery and motor recovery cannot be expected, or after failure or incomplete recovery after nerve repair. The goal of tendon transfers is to restore wrist, finger and thumb extension. For wrist extension, the use of pronator teres is well accepted. The best tendon transfer for finger extension is debated. This can be restored doing a flexor carpi ulnaris (FCU), flexor carpi radialis or flexor digitorum superficialis (FDS) to extensor digitorum communis transfer. Regarding thumb extension and abduction, a palmaris longus (PL) or one FDS tendon to the rerouted extensor pollicis longus (EPL) transfer can be performed. If a transfer is done on the EPL without rerouting it, abduction can be restored by doing a tendon transfer to the abductor pollicis longus (APL) or an APL tenodesis. The different tendon transfer options are selected based on the surgeon's preference, and most importantly, discussed with the patients to define the objectives together. The transfer is chosen based on the clinical examination (high or low radial nerve palsy, tendon available for transfer like PL, wrist mobility) and based on the patient's needs and expectations (activities requiring the FCU, finger independence, independence of thumb extension or abduction). If the surgical rules and the postoperative instructions for rehabilitation are followed, tendon transfers for radial nerve palsy regularly produce very satisfactory results.

Nerve transfers in the upper extremity: A review

Injury of the brachial plexus and peripheral nerve often result in significant upper extremity dysfunction and disability. Nerve transfers are replacing other techniques as the gold standard for brachial plexus and other proximal peripheral nerve injuries. These transfers require an intimate knowledge of nerve topography, a technically demanding Intraneural dissection and require extensive physical therapy for retraining. In this review, we present a summary of the most widely accepted nerve transfers in the upper extremity described in the current literature.

The use of chimeric musculocutaneous posterior interosseous artery flaps for treatment of osteomyelitis and soft tissue defect in hand

INTRODUCTION

There is growing evidence of the superior ability of muscular tissue to clear bacterial bone infection. Unfortunately, in the hand, there are almost no small local muscular flaps, and muscular transfers to the hand are mainly microsurgical free transfers. In this report, we present the results of the use of a chimeric posterior interosseous flap including part(s) of the forearm muscles to treat osteomyelitis and soft tissue defect of hand from a series of patients.

PATIENTS AND METHODS

Four male patients with an average age of 32 years (range 20-46 years), were affected by acute osteomyelitis in hand. Previous fracture fixation with percutaneous K-wires was the cause of bone infection in three case. In one case, the osteomyelitis was a consequence of an open fracture. The bones affected were four metacarpals and one proximal phalanx, all with a minimal cortical defect (from the K-wire) obscuring a larger medullary infection, which required extensive bone and overlying soft tissue debridement, leaving a soft tissue defect to be reconstructed of size ranging from 2 x 4 cm to 5 x 7 cm. The soft tissue defects were due to concomitant superficial infection and consequent debridement. All patients were treated with bone debridement and a chimeric posterior interosseous flap, which included part of the extensor digiti minimi and/or extensor carpi ulnaris to fill the intramedullary canal of the bones. No fixation of bone was necessary.

RESULTS

The skin paddle of the flaps ranged from 2 x 5 cm to 5 x 6 cm, replicating the defect area, plus a teardrop tail of skin circa 1.5 cm wide and as long as the pedicle of the flap. The muscular components of the flaps used to fill the intramedullary canals ranged from 1 x 1 x 1.5 cm to 1.5 x 1.5 x 4 cm. All flaps survived and osteomyelitis resolved in all cases without major complications. At the final follow-up at 16 months (range 12-26 months), assessment of the hands using TAM, Power Grip and Key Pinch Strength measurements and, where appropriate, Kapandji scores, demonstrated satisfactory hand function.

CONCLUSION

The chimeric posterior interosseous flap including part of the muscles of the forearm may be a robust solution for augmenting the flap bulk and may be used in cases of severe osteomyelitis of the hand.

“In Situ Vascular Nerve Graft” for Restoration of Intrinsic Hand Function: An Anatomical Study

Background: In combined high median and ulnar nerve injury, transfer of the posterior interosseous nerve branches to the motor branch of the ulnar nerve (MUN) is previously described in order to restore intrinsic hand function. In this operation a segment of sural nerve graft is required to close the gap between the donor and recipient nerves. However the thenar muscles are not innervated by this nerve transfer. The aim of the present study was to evaluate whether the superficial radial nerve (SRN) can be used as an “in situ vascular nerve graft” to connect the donor nerves to the MUN and the motor branch of median nerve (MMN) at the same time in order to address all denervated intrinsic and thenar muscles.

Methods: Twenty fresh male cadavers were dissected in order to evaluate the feasibility of this modification of technique. The size of nerve branches, the number of axons and the tension at repair site were evaluated.

Results: This nerve transfer was technically feasible in all specimens. There was no significant size mismatch between the donor and recipient nerves

Conclusions: The possible advantages of this modification include innervation of both median and ulnar nerve innervated intrinsic muscles, preservation of vascularity of the nerve graft which might accelerate the nerve regeneration, avoidance of leg incision and therefore the possibility of performing surgery under regional instead of general anesthesia. Briefly, this novel technique is a viable option which can be used instead of conventional nerve graft in some brachial plexus or combined high median and ulnar nerve injuries when restoration of intrinsic hand function by transfer of posterior interosseous nerve branches is attempted.

The Relationships Between Surface Measurements and Underlying Tendon Autograft Length for Upper Extremity Reconstructive Surgery

PURPOSE

The availability of tendon grafts is an important consideration for successful upper extremity reconstructive surgery, including flexor or extensor tendon reconstructions, tendon transfers, and ligament reconstructions. Graft selection is based on availability, expendability, ease of harvest, and length. Given variations in patient height and extremity length, existing average values may provide suboptimal insight into actual tendon lengths available. The purpose of this study is, therefore, to pursue a method of estimating available donor tendon lengths based on easily measured anatomical surface landmarks.

METHODS

Thirty cadaveric upper and lower extremity limbs were dissected and the length of commonly harvested tendon grafts including the palmaris longus, extensor indicis proprius, extensor digiti minimi, plantaris, and second long toe extensor was measured. Surface forearm length (from finger tip to cubital fossa) and surface fibular length (from lateral malleolus to fibular head) were also measured. Correlations between surface measurements and underlying tendon lengths were analyzed, and linear models were generated that predicted tendon length as a function of surface measurements.

RESULTS

Surface measurements were correlated with underlying tendon length (R = 0.46 - 0.66). Linear models could predict tendon lengths based on surface measurements. A ratio of donor tendon length compared with the limb segment measured was established for each tendon and can be applied to estimate donor tendon length. For the upper extremity tendons, the multipliers for the palmaris longus, extensor indicis proprius, and extensor digiti minimi were 0.51, 0.20, and 0.18, respectively. Lower extremity tendon ratios for the plantaris and extensor digitorum longus were 0.69 and 0.60, respectively.

CONCLUSIONS

Although length of available donor tendon can be a limiting variable at the time of surgery, surgeons may be better able to estimate underlying tendon lengths using easily obtained superficial measurements.

CLINICAL RELEVANCE

Information obtained from these cadaveric measurements may aid in preoperative planning in hand and upper extremity surgery.

Transfer of extensor digiti minimi and extensor carpi ulnaris nerve branches to the intrinsic motor nerve branches: A histological study on cadaver

BACKGROUND

In cases of high ulnar and median nerve palsy, result of nerve repair in term of intrinsic muscle recovery is unsatisfactory. Distal nerve transfer can alleviate the regeneration time and improve the results. Transfer of the extensor digiti minimi (EDM) and extensor carpi ulnaris (ECU) nerve branches to the deep branch of ulnar nerve (DBUN)/recurrent branch of median nerve (RMN) at wrist had been used to restore intrinsic hand function but, incomplete recovery occurred. The axon count at the donor nerve has a strong influence on the final results.

HYPOTHESIS

This cadaveric study aims to analyses the histology of this nerve transfer to evaluate whether these donor nerves are suitable for this transfer or another donor nerve may be considered.

MATERIALS AND METHODS

Ten cadaveric upper limbs dissected to identify the location of the EDM, ECU, RMN and DBUN. Surface area, fascicle count, and axon number was determined by histological methods.

RESULTS

The mean of axon number in the EDM, ECU, RMN and DBUN branches was 5931, 7355, 30960 and 35426, respectively. In this study, the number of axons in the EDM and ECU branches was 37% (13281/35426) of that in the DBUN. Also, the number of axons in the EDM and ECU branches was 42% (13281/30960) of that in the RMN.

CONCLUSION

The axon count data showed an unfavorable match between the EDM, ECU and DBUN/RMN. Therefore, it is suggested that another donor nerve with higher axon number to be considered.

TYPE OF STUDY

Cadaver study (histological study).

Supinator to ulnar nerve transfer via in situ anterior interosseous nerve bridge to restore intrinsic muscle function in combined proximal median and ulnar nerve injury: a novel cadaveric study

BACKGROUND

In cases of high ulnar nerve palsy, result of nerve repair in term of intrinsic muscle recovery is unsatisfactory. Distal nerve transfer can diminish the regeneration time and improve the results. But, there was no perfect distal nerve transfer for restoring intrinsic hand function in combined proximal median and ulnar nerve injuries. This cadaveric study aims to evaluate the possibility and feasibility of supinator nerve transfer to motor branch of ulnar nerve (MUN).

METHODS

Ten cadaveric upper limbs dissected to identify the location of the supinator branch, anterior interosseous nerve (AIN), and MUN. The AIN was cut from its origin and transferred to the supinator branches. Also, the AIN was distally cut and transferred to the MUN. After nerve coaptation, surface area, fascicle count, and axon number were determined by histologic methods.

RESULTS

In all limbs, the proximal and distal stumps of AIN reached the supinator branch and the MUN without tension, respectively. The mean of axon number in the supinator, proximal stump of AIN, distal stump of AIN and MUN branches were 32,426, 45,542, 25,288, and 35,426, respectively.

CONCLUSIONS

This study showed that transfer of the supinator branches to the MUN is possible via the in situ AIN bridge. The axon count data showed a favorable match between the supinator branches, AIN, and MUN. Therefore, it is suggested that this technique can be useful for patients with combined high median and ulnar nerve injuries.

High Ulnar Nerve Injuries: Nerve Transfers to Restore Function

Peripheral nerve injuries are challenging problems. Nerve transfers are one of many options available to surgeons caring for these patients, although they do not replace tendon transfers, nerve graft, or primary repair in all patients. Distal nerve transfers for the treatment of high ulnar nerve injuries allow for a shorter reinnervation period and improved ulnar intrinsic recovery, which are critical to function of the hand.

Management and complications of traumatic peripheral nerve injuries

This article provides an overview of the management of traumatic peripheral nerve injuries. It examines the basic pathophysiology of peripheral nerve injuries, along with the clinical presentation, diagnostic work-up, and treatment options and outcomes for the various classifications of traumatic peripheral nerve injuries.

Principles of nerve repair in complex wounds of the upper extremity

Peripheral nerve injuries are common in the setting of complex upper extremity trauma. Early identification of nerve injuries and intervention is critical for maximizing return of function. In this review, the principles of nerve injury, patient evaluation, and surgical management are discussed. An evidence-based approach to nerve reconstruction is reviewed, including the benefits and limitations of direct repair and nerve gap reconstruction with the use of autografts, processed nerve allografts, and conduits. Further, the principles and indications of commonly used nerve transfers in proximal nerve injuries are also addressed.

Advances in nerve transfer surgery

Peripheral nerve injuries are devastating injuries and can result in physical impairments, poor functional outcomes and high levels of disability. Advances in our understanding of peripheral nerve regeneration and nerve topography have lead to the development of nerve transfers to restore function. Over the past two decades, nerve transfers have been performed and modified. With the advancements in surgical management and recognition of importance of cortical plasticity, motor-reeducation and perioperative rehabilitation, nerve transfers are producing improved functional outcomes in patients with nerve injuries. This manuscript explores the recent literature as it relates to current nerve transfer techniques and advances in post-operative rehabilitation protocols, with a focus on indications, techniques and outcomes.

Direct radial to ulnar nerve transfer to restore intrinsic muscle function in combined proximal median and ulnar nerve injury: case report and surgical technique

A distal median to ulnar nerve transfer for timely restoration of critical intrinsic muscle function is possible in isolated ulnar nerve injuries but not for combined ulnar and median nerve injuries. We used a distal nerve transfer to restore ulnar intrinsic function in the case of a proximal combined median and ulnar nerve injury. Transfer of the nonessential radial nerve branches to the abductor pollicis longus, extensor pollicis brevis, and extensor indicis proprius to the motor branch of the ulnar nerve was performed in a direct end-to-end fashion via an interosseous tunnel. This method safely and effectively restored intrinsic function before terminal muscle degeneration.