What triggers in trigger finger? The flexor tendons at the flexor digitorum superficialis bifurcation.

To define the role of the flexor tendons in trigger finger, a high-resolution ultrasound examination was performed in 20 trigger fingers and 20 normal contralateral digits in three digital postures: full extension, mid-flexion and near-full flexion. Precise measurements of diameter and cross-sectional area of the combined tendon mass were recorded at five clearly defined locations: summit of the metacarpal head, proximal lip of the proximal phalanx (PP) and at 1/8, 1/4 and 1/2 length of the PP. In the normal tendons, there was an anatomical thickening, not previously appreciated at 1/4 length PP, in the region of the FDS bifurcation. This anatomical region moved proximally on finger flexion to the A1 pulley. In trigger fingers, the flexor tendons had greater diameter (sagittal view) and cross-sectional area than the normal side at all locations (p < 0.01, p < 0.001), with an even greater increase in diameter in the FDS bifurcation area (p < 0.001). Trigger fingers also had thicker A1 pulleys (p < 0.001). Triggering occurs on flexing the finger when the enlarged combined flexor tendon mass at the specific anatomical region of the FDS bifurcation impacts on the thickened A1 pulley, resisting its excursion.

An abnormality in glucocorticoid receptor expression differentiates steroid responders from nonresponders in keloid disease.

BACKGROUND: Glucocorticoids (GCs) are first-line treatment for keloid disease (KD) but are limited by high incidence of resistance, recurrence and undesirable side-effects. Identifying patient responsiveness early could guide therapy. METHODS: Nineteen patients with KD were recruited at week 0 (before treatment) and received intralesional steroids. At weeks 0, 2 and 4, noninvasive imaging and biopsies were performed. Responsiveness was determined by clinical response and a significant reduction in vascular perfusion following steroid treatment, using full-field laser perfusion imaging (FLPI). Responsiveness was also evaluated using (i) spectrophotometric intracutaneous analysis to quantify changes in collagen and melanin and (ii) histology to identify changes in epidermal thickness and glycosaminoglycan (GAG) expression. Biopsies were used to quantify changes in glucocorticoid receptor (GR) expression using quantitative reverse transcriptase polymerase chain reaction, immunoblotting and immunohistochemistry. RESULTS: At week 2, the FLPI was used to separate patients into steroid responsive (n = 12) and nonresponsive groups (n = 7). All patients demonstrated a significant decrease in GAG at week 2 (P < 0.05). At week 4, responsive patients exhibited significant reduction in melanin, GAG, epidermal thickness (all P < 0.05) and a continued reduction in perfusion (P < 0.001) compared with nonresponders. Steroid-responsive patients had increased GR expression at baseline and showed autoregulation of GR compared with nonresponders, who showed no change in GR transcription or protein. CONCLUSIONS: This is the first demonstration that keloid response to steroids can be measured objectively using noninvasive imaging. FLPI is a potentially reliable tool to stratify KD responsiveness. Altered GR expression may be the mechanism gating therapeutic response.

Enhanced early sensory outcome after nerve repair as a result of immediate post-operative re-learning: a randomized controlled trial.

We assessed the use of guided plasticity training to improve the outcome in the first 6 months after nerve repair. In a multicentre randomized controlled trial, 37 adults with median or ulnar nerve repair at the distal forearm were randomized to intervention, starting the first week after surgery with sensory and motor re-learning using mirror visual feedback and observation of touch, or to a control group with re-learning starting when reinnervation could be detected. The primary outcome at 3 and 6 months post-operatively was discriminative touch (shape texture identification test, part of the Rosen score). At 6 months, discriminative touch was significantly better in the early intervention group. Improvement of discriminative touch between 3 and 6 months was also significantly greater in that group. There were no significant differences in motor function, pain or in the total score. We conclude that early re-learning using guided plasticity may have a potential to improve the outcomes after nerve repair. LEVEL OF EVIDENCE II.

The cellular biology of tendon grafting.

We investigated the cellular biology of tendon grafting in a mouse model using green fluorescent protein mismatch grafting and quantitative immunohistochemistry of molecular markers for inflammation, proliferation, collagen synthesis, cell death, and myofibroblast/pericyte expression. We provide a detailed analysis of the healing characteristics during the phases of inflammation, synthesis, and remodelling. Our findings indicated that survival of the cells in the grafted tendon was finite. Syngenic and autologous grafts provoked a similar cellular reaction and all grafts healed. Cells in the graft contributed significantly to collagen synthesis and do have a role in healing.

The anatomy and function of Cleland's ligaments.

The cutaneous ligaments of the digits have been recognized by anatomists for several centuries, but the best known description is that of John Cleland. Subsequent varying descriptions of their morphology have resulted in the surgical community having an imprecise view of their structure and dynamic function. We micro-dissected 24 fresh frozen fingers to analyze the individual components of Cleland's ligamentous system. Arising from the proximal interphalangeal (PIP) joint, proximal, and sometimes middle phalanx, we found strong ligaments that ran proximally (PIP-P) and distally (PIP-D). On each side of each finger there was a PIP-P ligament present, which passed obliquely from the lateral side of the proximal and sometimes middle phalanx towards its insertion into the skin at the level of the proximal phalanx. The distal (PIP-D) ligaments were found to pass obliquely distally on the radial and ulnar aspects of the digit towards cutaneous insertions around the middle phalanx. A similar arrangement exists more distally with fibres originating from the DIP joint and middle phalanx (the DIP-P pass obliquely proximally, and the DIP-D, distally). Each individual PIP ligament consisted of three different layers originating from fibres overlying the flexor tendon sheath, periosteum or joint capsule, and extensor expansion. Ligaments arising at the DIP joint had two layers equivalent to the anterior two layers of the proximal ligaments. Cleland's ligaments act as skin anchors maintaining the skin in a fixed relationship to the underlying skeleton during motion and functional tasks. They also prevent the skin from 'bagging', protect the neurovascular bundle, and create a gliding path for the lateral slips of the extensor tendon.

The mechanical interaction between three geometric types of nylon core suture and a running epitenon suture in repair of porcine flexor tendons.

The effect of core suture geometry on the mechanical interaction with the epitenon suture in terms of gap prevention, failure strength and mode of failure was investigated in a flexor tendon repair model. A total of 48 porcine flexor tendons were repaired using three techniques with distinct core suture geometry: single Kessler; double Kessler; and cruciate repair. Cyclic linear testing was carried out with and without a simple running epitenon suture. At failure load the epitenon suture reduced gapping by 87% in the double Kessler, 42% in the single Kessler and 15% in cruciate repairs. It increased the strengths of the repairs by 58%, 33% and 24%, respectively. Kessler repairs failed mainly by suture rupture, with and without epitenon suture, but cruciate repairs failed mainly by suture pull-out. The epitenon suture did not have a significant mechanical effect on the three repairs. Rather, its effect varied with the core suture geometry. The greatest effect occurred with double Kessler repairs.

Tom Gibson, Plastic Surgeon (1915-93): Allograft rejection by the immune system and prediction of free tissue transplantation.

Tom Gibson made enormous contributions to the modern development of Plastic and Reconstructive Surgery. His key 1943 paper 'The fate of skin homografts in man' described the 'second set' phenomenon attributing graft rejection to an immunological phenomenon. Later in his career he visualised the concept of microvascular tissue transplantation and inspired many young surgeons through his various roles of Director of the unit at Canniesburn Hospital, Professor of Bioengineering and President of the Royal College of Physicians and Surgeons of Glasgow.

Arterial injuries at the elbow carry a high risk of muscle necrosis and warrant urgent revascularisation.

INTRODUCTION: Revascularisation following axial arterial system injury is effective in upper limb salvage but necrosis of muscle, the tissue most sensitive to ischaemia, may still occur. We examined the frequency of necrosis, its related factors and its functional significance. METHODS: The clinical findings and operative management of 13 patients with injuries at the elbow referred to 2 plastic surgical hand surgery units over a 30-month period were reviewed. Good outcome was defined as minimal impairment with return to previous occupation, intermediate outcome as moderate impairment with change in occupation and poor outcome as major functional loss preventing work. RESULTS: Seven patients injured the brachial and six injured both the radial and ulnar arteries. Concomitant injuries were severe with nerve injuries in 11 and muscle damage in 12 patients. Functional outcome was good in four cases, intermediate in four and poor in five. Muscle necrosis developed in four brachial artery injuries. In all four cases, initial successful revascularisation failed post-operatively. Case review revealed delayed recognition in three cases where pain heralded ischaemia but distal skin circulation and pulses were adequate. Of patients with necrosis, three had a poor outcome and one had an intermediate outcome. CONCLUSIONS: The risk of muscle necrosis must be considered when managing these injuries, particularly if initial revascularisation is unsuccessful. Every effort should be made to optimise repair technique and post-operative monitoring. Limb salvage is no longer enough. Fully viable muscle is necessary to restore function and livelihoods.

Management of severe Dupuytren's contracture of the proximal interphalangeal joint with use of a central slip facilitation device.

Thirty-eight fingers in 27 patients with Dupuytren's contracture of the proximal interphalangeal joint (PIPJ) in excess of 70° were treated using a staged technique. The first stage involved applying a mini external fixator across the PIPJ for continuous extension over 6 weeks with intensive hand therapy to maintain mobility of the joint and help correct the deformity. Twice weekly during hand therapy sessions the tension of the elastic band across the mini ex-fix was increased, allowing that full active flexion of the PIPJ against the elastic band could still be achieved. The second stage, 4 weeks after the external fixator was applied, involved an open palm technique of fasciectomy for the contracted cords restricting metacarpophalangeal joint movement and dermofasciectomy with full-thickness skin grafting over the proximal phalanx for bands restricting PIPJ movement. The external fixator was used to maintain active extension force until the graft healed. It was generally removed in the outpatient clinic under ring block 2 weeks after the second stage procedure. The patients were followed for a mean of 20.6 (6-48) months. The mean preoperative PIPJ deformity improved from 75° to 37° postoperatively. Overall, 69% of results were rated as good to excellent. Only one patient reported any on-going functional problems. There were eight cases of pin site infections and one case each of loose pins, osteoarthritics at the PIPJ, reflex sympathetic dystrophy, and disease recurrence needing PIPJ fusion. We conclude that our simple staged procedure is a valid alternative in the management of severe Dupuytren's PIPJ contracture.

Two-finger homodigital web advancement flap.

Fingertip amputation is a common hand injury and various techniques for reconstruction have been described. Important considerations to take into account when planning reconstruction are maintaining length and preserving function. This paper describes a technique for reconstructing the amputated fingertips of two adjacent digits.

Fibroblasts from the growing margin of keloid scars produce higher levels of collagen I and III compared with intralesional and extralesional sites: clinical implications for lesional site-directed therapy.

BACKGROUND: Overproduction of collagen and its abnormal assembly are hallmarks of keloid scars. Type I/III collagen ratios are altered in keloids compared with normal skin. Fibroblasts from different sites in keloid tissue, perilesional compared with intralesional and extralesional sites, show differential apoptosis and contraction. Additionally, early vs. later cell culture passages display differential collagen expression. We therefore hypothesize that keloid fibroblasts from the growing margin of the keloid express higher levels of collagen type I and III, and that collagen production is altered by extended cell culture passage. OBJECTIVES: (i) To measure collagen I and III at mRNA and protein levels quantitatively in keloid fibroblasts, growth media and tissue sections; and (ii) to perform tissue staining for collagen I and III expression in different lesional sites. METHODS: Keloid fibroblast cultures from intralesional, perilesional and extralesional sites (n = 8 separate keloid cases, yielding 64 biopsy samples) were established from passage 0 to passage 3. Collagen I and III mRNA was quantified using quantitative reverse transcription-polymerase chain reaction. We also measured the protein levels quantitatively by developing a highly specific and sensitive capture sandwich enzyme-linked immunosorbent assay. A novel in-cell Western blotting was carried out in addition to haematoxylin and eosin and Herovici staining on keloid tissue sections for collagen I and III. RESULTS: Collagen types I and III were significantly higher (P < 0·03) in fibroblasts from the growing margin (perilesional site) compared with extralesional and intralesional keloid biopsy sites. As the passage number increased, the amount of collagen I significantly (P < 0·05) decreased and the collagen I/III ratio also decreased. CONCLUSIONS: Our data show that cells from the growing margin of keloid scars have a higher production of collagen I and III compared with other lesional sites. Additionally, temporal extension of cell passage affects collagen production. Clinically these findings may influence selection and interpretation of extended cell passage and provide future direction for lesional site-specific therapy in keloid scars.

Characterization of hyaluronan and TSG-6 in skin scarring: differential distribution in keloid scars, normal scars and unscarred skin.

BACKGROUND: Hyaluronan (HA) is a major component of the extracellular matrix (ECM) with increased synthesis during tissue repair. Tumour necrosis factor-stimulated gene-6 (TSG-6) is known to catalyze the covalent transfer of heavy chains (HC1 and HC2) from inter-α-inhibitor (IαI) onto HA, and resultant HC•HA complexes have been implicated in physiological and pathological processes related to remodelling and inflammation. OBJECTIVE: The aims of this study were to determine the expression of HA, TSG-6 and the IαI polypeptides in unscarred skin, normal scars and keloid scars. METHODS: Formalin-fixed paraffin-embedded sections of unscarred skin, normal scars and keloid scars were prepared from patient samples collected during scar revision surgery. Haematoxylin and eosin, as well as immunofluorescent staining for HA, TSG-6 and the three polypeptide chains of IαI (i.e. HC1, HC2 and bikunin) were performed. RESULTS: All skin types stained positive for TSG-6, HC1, HC2 and bikunin, associated with keratinocytes, fibroblasts and skin appendages all in close proximity to HA. Keloid lesions showed altered HA organization patterns compared with unscarred skin and normal scars. TSG-6 staining was significantly more intense in the epidermis compared with the dermis of all sample types. There was a significant reduction in TSG-6 levels within keloid lesions compared with the dermis of unscarred skin (P=0.017). CONCLUSION: TSG-6 is expressed in unscarred skin, where its close association with HA and IαI could give rise to TSG-6-mediated HC•HA formation within this tissue. A reduction in the beneficial effects of TSG-6, caused by diminished protein levels in keloid lesions, could contribute to this abnormal scarring process.

Shear-aggregated fibronectin with anti-adhesive properties.

Biomaterials based on proteins, such as fibronectin, have the potential to guide cell and tissue behaviour during healing as a function of their unique mechanical and bioactive properties. Fibronectin has been reported as a scaffold for attachment of fibroblasts and subsequent deposition of collagen. We have recently developed a derivative process of shear-aggregated fibronectin that prevents cell attachment without causing cell death. This has potential applications in clinical situations where adhesions form across gliding surfaces and cause loss of function, e.g. peritoneal or flexor tendon adhesions. This in vitro study tested this derivative fibronectin biomaterial and its effects on aggressive adhesion-forming cells, using rabbit flexor tendon synovial fibroblasts. We investigated degradation of the novel biomaterial, and attachment of fibroblasts to glass coated with the biomaterial, relative to fibroblast attachment to uncoated and fibronectin-coated glass. We assessed infiltration of the derivative fibronectin biomaterial by fibroblasts and cytotoxicity of the biomaterial to fibroblasts. The interaction between fibroblasts and the derivative fibronectin biomaterial was visualized using time-lapse photography. The derivative fibronectin biomaterial dissolved by 88% of its mass by 3 weeks. Fibroblast attachment to the novel biomaterial was significantly reduced at 6 h. After 24 h of exposure to the novel biomaterial, fibroblasts did not migrate into it, there was no cell death and no attachment was seen using time-lapse. This novel derivative fibronectin biomaterial combines inhibition of fibroblast attachment with barrier effects and has suitable mechanical properties for surgical use in preventing adhesions in vivo.

Treatment of symptomatic abnormal skin scars with electrical stimulation.

OBJECTIVE: To evaluate the effect of non-invasive biofeedback electrical stimulation on symptomatic abnormal skin scars. METHOD: Thirty patients with over 140 scars with long-term pain and itch were recruited into the study. Patients monitored the intensity of symptoms (pain and itching) on a numerical rating scale. In addition, a modified Manchester scar scale was used to objectively assess digital photographs of each scar in terms of colour, contour, distortion and texture, while a non-invasive spectrophotometric intracutaneous analysis was used to monitor the scars' physical characteristics. RESULTS: The electrical stimulation device resulted in a clinically and statistically significant (p < 0.05) reduction of symptoms and scar scores. Pain and itch scores were both reduced to a median score of 0 by 2 months, from a baseline of 7 and 6 respectively. Scar scores were reduced from a baseline of 14 to a median score of 11 by 2 months. CONCLUSION: These results give a preliminary indication of the potential role of non-invasive biofeedback electrical stimulation in the management of chronic scar pain and itch. However, further large scale controlled studies are warranted to elucidate its overall efficacy and mechanistic action. CONFLICT OF INTEREST: Funding was provided from Fenzian Ltd for this study.

The cell biology of suturing tendons.

Trauma by suturing tendon form areas devoid of cells termed "acellular zones" in the matrix. This study aimed to characterise the cellular insult of suturing and acellular zone formation in mouse tendon. Acellular zone formation was evaluated using single grasping sutures placed using flexor tendons with time lapse cell viability imaging for a period of 12h. Both tension and injury were required to induce cell death and cell movement in the formation of the acellular zone. DNA fragmentation studies and transmission electron microscopy indicated that cells necrosed. Parallel in vivo studies showed that cell-to-cell contacts were disrupted following grasping by the suture in tensioned tendon. Without tension, cell death was lessened and cell-to-cell contacts remained intact. Quantitative immunohistochemistry and 3D cellular profile mapping of wound healing markers over a one year time course showed that acellular zones arise rapidly and showed no evidence of healing whilst the wound healing response occurred in the surrounding tissues. The acellular zones were also evident in a standard modified "Kessler" clinical repair. In conclusion, the suture repair of injured tendons produces acellular zones, which may potentially cause early tendon failure.

The microvacuolar system: how connective tissue sliding works.

The term 'fascia' has been applied to a large number of very different tissues within the hand. These range from aligned ligamentous formations such as the longitudinal bands of the palmar fascia or Grayson's and Cleland's ligaments, to the loose packing tissues that surround all of the moving structures within the hand. In other parts of the body the terms 'superficial' and 'deep fascia' are often used but these have little application in the hand and fingers. Fascia can be divided into tissues that restrain motion, act as anchors for the skin, or provide lubrication and gliding. Whereas the deep fascia is preserved and easily characterized in anatomical dissection, the remaining fascial tissue is poorly described. Understanding its structure and dynamic anatomy may help improve outcomes after hand injury and disease. This review describes the sliding tissue of the hand or the 'microvacuolar system' and demonstrates how movement of tissues can occur with minimal distortion of the overlying skin while maintaining tissue continuity.