Free Non-vascularized Toe Phalangeal Transfers in Symbrachydactyly: Outcome Analysis

Introduction Free nonvascularized toe phalangeal transfer is an established surgical option for the reconstruction of hypoplastic digits. The purpose of the present study was to evaluate our experience with this procedure and to assess bone growth and digit function as well foot morbidity. Material and Methods We retrospectively evaluated the clinical records for all children with symbrachydactyly submitted to free nonvascularized toe phalangeal transfer between 2002 and 2017. A total of 8 patients were included. We summoned the patients to an appointment to clinically assess the range of motion, the stability, and the alignment of the neo-joint. We radiographically measured the final length and the expected percentage of growth of the transferred phalanx. We also evaluated the foot for comorbidities. Results The mean age at the time of the first surgery was 19 months (range: 8–42 months). A total of 20 phalanges were harvested: 16 total proximal phalanges, 2 middle phalanges, 1 subtotal proximal phalanx, and 1 accessory thumb phalanx. The distal part of one proximal phalanx was trimmed because the skin pocket was too tight. Two patients underwent a secondary procedure to release the syndactyly. One transfer required revision surgery due to distal tip necrosis and exposition of the transferred phalanx. In the present series, the overall clinical and radiographic outcomes were compatible to those reported in other studies. Discussion The main limitation of the nonvascularized toe phalanx transfer is the preexisting soft tissue envelope of the finger and the limited growth potential of the transferred bone. Conclusion Irrespective of the amount of growth achieved in the transferred phalanx, the actual transfer and growth attained should not be viewed as the end result, but rather as a means of providing a stable and functional joint.

The Effect of Isolated Finger Stiffness on Adjacent Digit Function

Background: Isolated stiffness in a single finger can affect the function of adjacent digits and decrease overall hand function due to the quadriga phenomenon. This study objectively quantifies the dysfunctional impact of each individual stiff finger upon the remaining digits. Methods: Twenty-five individuals (10 men and 15 women) with a mean age of 31 years (range, 18-58 years) without any upper limb pathology, neuropathy, or systemic illness were recruited. Volar-based finger splints were used to hold individual digits of the dominant hand (24 right and 1 left) sequentially in full extension at the metacarpophalangeal (MCP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints. Motion of the remaining 3 nonsplinted digits was assessed using a finger goniometer and linear scale to measure the total active range of motion (TAM) and fingertip-to-distal palmar crease (DPC) distance. TAM before and after splinting for each digit was compared using 1-way analysis of variance (ANOVA). Results: Splinting of any individual finger resulted in a significant reduction in the TAM of all adjacent fingers, regardless of which finger was splinted ( P < .001). Digits immediately adjacent to the splinted finger were more heavily impacted compared with nonadjacent digits. Splinting of the ring finger produced the greatest detriment, with a 26% to 47% reduction in the TAM and a DPC distance greater than 40 mm in a third of participants. The index finger caused the least disturbance to remaining digital motion. Conclusions: Isolated finger stiffness causes a variable degree of dysfunction on adjacent normal digits. This emphasizes the need for a focused and proactive approach to restore full active motion following isolated finger injuries to prevent persistent functional sequelae of the hand.

A digit function with Thomae-like properties

Following a recent revival of interest in both Thomae's function and digit functions (see [1] and [2] respectively) we present here a function providing an appealing link between the two. The former, nowadays often cited in courses on real analysis, was given by Thomae in 1875; see also [3], [4] and [5]. This function, which we denote by g(x), has the following definition:where it is so be assumed that gcd (p, q) = 1 when x is rational.

Mallet Deformity in Sport

During a four month period 851 patients presented to the Edinburgh Orthopaedic Trauma Unit with an acute sporting injury. Eighteen (2%) patients had either a soft tissue or bony mallet deformity. Six different sports were identified with rugby accounting for eight of the 18 mallet deformities. All patients were treated with splintage. Fourteen patients returned questionnaires regarding subjective digit function following treatment and nine patients claimed excellent function. The average splinting time for this group was 6 weeks and sports were avoided for an average of 5 weeks. Mallet deformity accounts for a minority of sporting injuries, but excellent functional outcome can be achieved with splintage and avoidance of the causative sport while splinted.

Organization of Recurrent Inhibition and Facilitation in Motor Nuclei Innervating Ankle Muscles of the Cat

Turkin, Vladimir V., Katrina S. Monroe, and Thomas M. Hamm. Organization of recurrent inhibition and facilitation in motor nuclei innervating ankle muscles of the cat. J. Neurophysiol. 79: 778–790, 1998. The distribution of recurrent inhibition and facilitation to motor nuclei of muscles that act at the cat ankle joint was compared with the locomotor activity and mechanical action of those muscles described in published studies. Emphasis was placed on motor nuclei whose muscles have a principal action about the abduction—adduction axis and the pretibial flexors: tibialis posterior (TP), peroneus longus (PerL), peroneus brevis (PerB), the anterior part of tibialis anterior (TA) and extensor digitorum longus (EDL). Most intracellular recordings in spinalized, unanesthetized decerebrate cats showed only inhibitory or excitatory responses to antidromic stimulation of peripheral nerves, but mixed effects were also seen. Recurrent effects among motor nuclei of ankle abductors and adductors were not distributed uniformly. TP motoneurons received recurrent inhibition from most other nuclei active in stance and stimulation of the TP nerve inhibited these motor nuclei. Although PerB motoneurons are also active during stance, they received primarily facilitation from most motor nuclei. PerL received mixtures of inhibition and facilitation from all sources. Stimulation of the nerves to PerL, PerB, and peroneus tertius (PerT) produced weak recurrent inhibition and facilitation, even in homonymous motoneurons and motoneurons of Ia synergists. The ankle flexors TA and EDL displayed different patterns of recurrent inhibition and facilitation. TA motoneurons received prominent homonymous inhibition and inhibition from semitendinosus (St). EDL, whose activity profile differs from TA and which also acts at the digits, did not receive strong recurrent inhibition from either TA or St, nor did stimulation of the EDL nerve produce much inhibition. The distribution of recurrent inhibition and facilitation is correlated with the pattern of locomotor activity, but with exceptions that suggest an influence of mechanical action, particularly in the antagonistic interactions between TP and PerB. The extended pattern of recurrent inhibition, the reduction or absence of inhibition produced by motor nuclei with individualized functions or digit function and the prevalence of facilitation suggest that the recurrent Renshaw system is organized into inhibitory and disinhibitory projections that participate in the control of sets of motor nuclei engaged in rhythmic and stereotyped movements.