The purpose of this study was to compare the outcomes of bridge tendon grafts and end-to-side tendon transfers for treating closed ruptures of the flexor tendons in Zones 3 to 5 of the little finger. We selected the surgical procedure based on the passive distraction amplitude of the proximal part of the ruptured flexor tendon. Eleven patients comprised the bridge tendon graft group and ten patients comprised the end-to-side tendon transfer group. We found no significant between-group differences in the total active motion, percentage of total active motion, functional assessment by the Strickland and Glogovac criteria and grip strength compared with the unaffected hand. We believe that choosing the surgical procedure after determining the passive distraction amplitude of the ruptured tendon can be useful in clinical practice.Level of evidence: III.

Closed ruptures of the flexor digitorum profundus (FDP) tendon cause a loss of active flexion at the distal interphalangeal joint. Commonly referred to as a 'jersey finger' because of its association with tackling sports, the distal aspect of FDP is avulsed from its insertion on the distal phalanx in zone I, with or without a fragment of bone. Because of this classic injury mechanism and pattern, providers may not seek advanced imaging beyond plain radiographs. Although rare, injury to FDP more proximally may occur. More often this injury is associated with a weak underlying tendon because of repetitive microtrauma or anomalous anatomy, for example. We present a case of a closed rupture of the FDP in zone III, and stress the importance of maintaining a high clinical suspicion and the potential use of adjunct ultrasound imaging to localise the site of injury.

We report the results of interposition tendon grafts using the ipsilateral palmaris longus tendon in 12 patients with closed flexor digitorum profundus tendon ruptures in zone III or IV of 14 digits between June 2006 and October 2015. Before surgery, 2 patients were diagnosed with closed tendon ruptures that occurred after nonunion of hamate hook fractures. The other 10 patients were diagnosed with spontaneous tendon ruptures of unknown cause. In 2 of the 10 patients with spontaneous tendon rupture, the cause of the rupture was not found. In the other 8 patients, there was rough surface with deficient overlying soft tissue on the radial side of the hamate hook. In all cases, the ruptured flexor digitorum profundus was reconstructed by applying overtension on the tendon graft, causing greater flexion than for the other normal digits. Hamate hook excision was also performed on 10 subjects with abnormalities. Postoperatively, the patients were followed for an average of 22.5 months (range, 12-64 months). At the final follow-up, the mean Disabilities of the Arm, Shoulder, and Hand questionnaire score was 5.7 (range, 3.3-8.3). There were excellent results in all 14 digits according to Strickland and Glogovac criteria. The mean total active motion was 167 degrees (range, 160-180 degrees). There were no surgical complications, including infection, adhesions, or tendon rerupture. There were excellent clinical results with the interposition tendon graft using palmaris longus for closed tendon rupture in zone III or IV of the hand. Applying overtension to the grafted tendon appears to be beneficial.

Tissue engineering is believed to have great potential for the reconstruction of the hand after trauma, congenital absence and tumours. Due to the presence of multiple distinct tissue types, which together function in a precisely orchestrated fashion, the hand counts among the most complex structures to regenerate. As yet the achievements have been limited. More recently, the focus has shifted towards scaffolds, which provide a three-dimensional framework to mimic the natural extracellular environment for specific cell types. In particular their surface structures (or topographies) have become a key research focus to enhance tissue-specific cell attachment and growth into fully functioning units. This article reviews the current understanding in hand tissue engineering before focusing on the potential for scaffold topographical features on micro- and nanometre scales to achieve better functional regeneration of individual and composite tissues.

Spontaneous flexor intratendinous ruptures are rare and incompletely understood. They occur within the substance of the tendon, and in the absence of underlying pathological processes or direct trauma. We present an unusual case of spontaneous flexor digitorum profundus tendon rupture in the palm.