Split flexor pollicus longus tendon transfer for stabilization of the thumb interphalangeal joint: a cadaveric and clinical study

Expert consensus on the surgical evaluation and management of upper extremity spasticity in adults

In the last decade there has been incredible interest and advancement in the surgical care of adult patients with upper motor neuron (UMN) injuries. Spasticity represents a prevalent and debilitating feature of UMN syndrome, which can result from cerebral palsy, spinal cord injury, cerebrovascular accident and traumatic or anoxic brain injury. While several diagnostic tools and management strategies have been described for upper limb spasticity, evidence-based practice guidelines do not currently exist due to low patient volume and a paucity of surgeons routinely performing surgeries in UMN syndrome patients. As such, expert consensus may help provide guidance for patients, therapists and clinicians alike. In this article an expert panel was assembled, and the Delphi method was utilized to present diagnostic considerations, define operative indications, discuss surgical treatment modalities and encourage a standard set of outcome measures for patients with upper extremity spasticity.

Upper-Extremity Reconstruction in Tetraplegia: A Critical Analysis Review

Management of tetraplegia should be individualized to a patient's particular deficiencies and functional goals. Surgical decision-making for upper-extremity reconstruction in patients with tetraplegia relies on a thorough physical examination to determine which nerves and muscles remain under volitional control with adequate strength for transfer. Peripheral nerve transfers, either in conjunction with or in place of traditional tendon transfers, enable providers to offer an expanded set of surgical options for patients with tetraplegia who are seeking upper-extremity reconstruction. All upper-extremity reconstructive efforts should be carefully considered with regard to their potential effects on the availability of future reconstructive efforts.

The Dorsal Aponeurosis of the Thumb

PURPOSE

To evaluate the thumb dorsal aponeurosis anatomy. Consideration of structural differences between the fingers and thumb will provide an improved clinical understanding of the thumb dorsal aponeurosis anatomy.

METHODS

Ten fresh cadaver hands from 5 patients with an average age of 31.6 (range, 22-41) years were dissected. The thenar muscles were identified and insertion sites were documented. The fibers of the dorsal aponeurosis and contributions were identified.

RESULTS

The flexor pollicis brevis superficial head contributed to the radial fibers of the dorsal aponeurosis in 8 specimens and contributed to the deep head in 1 specimen. The abductor pollicis brevis provided fibers to the radial dorsal aponeurosis in all 10 specimens. The oblique and transverse heads of the adductor pollicis contributed to the ulnar dorsal aponeurosis in 8 and 9 hands, respectively. The fibers of the intrinsic apparatus were composed of 3 major types: transverse, oblique, and long.

CONCLUSIONS

This investigation provides a detailed anatomic study of the dorsal aponeurosis of the thumb with observation of both intrinsic and extrinsic contributions.

CLINICAL RELEVANCE

Understanding the anatomy of the dorsal aponeurosis of the thumb remains important not only for evaluation of the classic Stener lesion, but also for the appropriate treatment of deformity, contracture, and neuromuscular disorders involving the thumb.

Tendon Transfers for Combined Peripheral Nerve Injuries

Combined peripheral nerve injuries present a unique set of challenges to the hand surgeon when considering tendon transfers. They are often associated with severe soft tissue trauma, including lacerations to remaining innervated muscles and tendons, significant scar formation, and substantial sensory loss. In the case of combined nerve injuries, there are typically fewer options for tendon transfers due to fewer tendons of shared function that are expendable as well as associated injuries to tendon or muscle bellies. As such, careful preoperative planning must be performed to make the most of remaining muscle tendon units.

Ulnar Nerve Tendon Transfers for Pinch

Power and tip pinch are an integral part of intrinsic hand function that can be significantly compromised with dysfunction of the ulnar nerve. Loss of power pinch is one component that can significantly affect an individual's ability to perform simple daily tasks. Tip pinch is less affected, as this task has significant contributions from the median nerve. To restore power pinch, the primary focus must be on restoring the action of the adductor pollicis primarily, and if indicated the first dorsal interosseous muscle and flexor pollicis brevis.

Split flexor pollicis longus tendon transfer to A1 pulley for correction of paralytic Z deformity of the thumb

PURPOSE

To test the hypothesis that split flexor pollicis longus (FPL) transfer to the A1 pulley will correct a thumb paralytic Z deformity and that the transfer can be subjected to early postoperative active mobilization protocol.

METHODS

In a prospective trial, 19 consecutive thumbs with ulnar or combined ulnar and median nerve paralysis received split FPL transfer to the thumb A1 pulley and active mobilization of transfer after 48 hours. Outcomes were assessed by correction of Z deformity during pinch, tendon transfer insertion pullout during early active mobilization, range of motion at the thumb metacarpophalangeal and interphalangeal joints, and postoperative treatment time. Data from historical records of 20 thumbs with split FPL to extensor pollicis longus (EPL) and 3 weeks' immobilization, treated before the prospective trial in the same institution, were used for comparison.

RESULTS

All 19 thumbs with split FPL to A1 pulley achieved Z deformity correction at discharge from rehabilitation. There was no incidence of transfer insertion pullout during active mobilization, and patients were discharged 22 days earlier than the controls who received transfer of FPL to EPL insertion. Seventeen thumbs were available for follow-up more than 1 year after the index procedure. Fifteen thumbs retained deformity correction, and 2 had recurrence of Z deformity. The interphalangeal joint had considerably greater active motion following split FPL to A1 pulley compared with transfer of split FPL to EPL insertion.

CONCLUSIONS

This study supports the hypothesis. Split FPL tendon transfer to thumb A1 pulley can correct paralytic thumb Z deformities and be mobilized early for transfer re-education. Improved interphalangeal joint active motion and reduced treatment time are added advantages over FPL transfer to the EPL insertion.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic III.

Late reconstruction for ulnar nerve palsy

Long term paralysis of the ulnar nerve is associated with an array of specific deficits and deformities. The numerous options for reconstruction are reviewed, as well as the specific patient considerations in selecting a strategy. An approach to late reconstruction for late ulnar nerve palsy is presented based upon the authors' experience and the available literature.

Implanted neuroprostheses for restoration of hand function in tetraplegic patients

Restoration of hand function through functional electrical stimulation allows tetraplegic patients to use existing abilities to control paralyzed muscles. In patients with C5 or C6 spinal cord injuries, implanted upper extremity neuroprostheses use functional electrical stimulation technology to power hand and arm muscles. A variety of devices, often using contralateral shoulder motion, sends signals via a small external controller and transmitting coil to an implanted stimulator. The stimulator powers designated upper extremity muscles via implanted electrodes. The surgical procedure is minimally invasive and easily reversed. Palmar and lateral grasp, among other functions, can be reliably restored, leading to significant improvements in functional capacity. High user satisfaction, low complication rates, and recent advances in technology and control systems contribute to the success of this technology in the treatment of devastating spinal cord injuries.

The unoperated hand: the role of passive forces in hand function after tetraplegia

Passive forces play a large role in hand function after tetraplegia. Most individuals with tetraplegia choose not to undergo surgical reconstruction of hand function and, therefore, depend on the passive properties of their musculoskeletal system to perform functional tasks. Knowledge of the levels of force needed to perform many of these tasks is lacking. Understanding the mechanics of producing passive force is important for designing adaptive tools and other devices for tetraplegic individuals. Knowledge of the passive properties of the upper extremity is important in forming treatment strategies. The passive forces produced for change to the tenodesis grasp are small but useful to the individual. Since these forces arise from basic anatomy and muscle function, they are important even after surgical restoration of hand function. Compensatory strategies for the unoperated hand probably play a role in the operated hand. The approach to surgical restoration of grasp must consider how passive forces contribute to functional outcome.

Changes in muscle moment arms following split tendon transfer of tibialis anterior and tibialis posterior

Moment arms of tibialis anterior (TA) and tibialis posterior (TP) about the subtalar and talocrural joint axes were measured in anatomic specimens both before and after split tendon transfers. These procedures are commonly performed to correct hindfoot varus, a gait deformity that is often seen in patients with cerebral palsy, stroke, and brain injury. Split tendon transfer significantly reduced the inversion moment arms of tibialis anterior and tibialis posterior at all subtalar joint angles except for the most everted position in the case of TA. Changes in subtalar joint moment arms produced by split tendon transfer, especially those seen in TA, were variable, suggesting that the procedure may be susceptible to technical errors, especially related to balancing tensions in the medial and lateral tendon halves. Talocrural joint moment arms of both muscles were preserved following split tendon transfer. This study presents the first measurements of the moment arms of split transferred muscles. These characterizations of the mechanics of split tendon transfer will aid in the planning and assessment of these procedures.