Endoscopy-assisted subfascial anterior transposition of the ulnar nerve for the treatment of cubital tunnel syndrome.

BACKGROUND: Many techniques have been described to relieve the compression and reduce subluxation of the ulnar nerve following surgery. The subfascial anterior transposition of the ulnar nerve (SfATUN) is one described technique, but involves a long scar, risk of injury to the medial antebrachial cutaneous nerve, and possible nerve ischemia from anterior transposition. We assessed a more refined approach of endoscopy-assisted SfATUN for the treatment of cubital tunnel syndrome. METHODS: A consecutive case series of 21 patients (15 males and 6 females) with evidence of nerve subluxation after ulnar nerve decompression were operated using an endoscopy-assisted SfATUN. Each patient was assessed with pre- and postoperative nerve conduction studies, McGowan grading, and recovery of grip strength. RESULTS: The average age of patients was 54 years (range 23-74 years), and they were followed up for a mean of 9 months (range 3-22 months). Preoperative McGowan grades were eight grade II and 13 grade III. Eighteen of the 21 patients showed improvement, including improvement by two McGowen grades in 8 patients and improvement by one grade in 10 patients. Three grade III patients did not show improvement in grading after surgery. A proportion of 90% of patients showed significant improvements in motor nerve conduction velocity of the ulnar nerve across the elbow (p < 0.001), and all showed some improvement in grip strength (p < 0.001). One patient underwent redo neurolysis. CONCLUSION: A combination of endoscopy-assisted SfATUN allows for decompression transposition and reduced strain on the ulnar nerve through a small scar. This is now our standard approach for cubital tunnel syndrome and the "unstable" nerve.

Tendon grafts: their natural history, biology and future development.

The use of tendon grafts has diminished as regimes of primary repairs and rehabilitation have improved, but they remain important in secondary reconstruction. Relatively little is known about the cellular biology of grafts, and the general perception is that they have little biological activity. The reality is that there is a wealth of cellular and molecular changes occurring with the process of engraftment that affect the quality of the repair. This review highlights the historical perspectives and modern concepts of graft take, reviews the different attachment techniques and revisits the biology of pseudosheath formation. In addition, we discuss some of the future directions in tendon reconstruction by grafting, which include surface modification, vascularized tendon transfer, allografts, biomaterials and cell-based therapies.

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 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.

The cellular effect of a single interrupted suture on tendon.

The effects on cell and matrix morphology of a single interrupted suture are described in rabbit (vascular) and mouse (avascular) digital flexor tendons. This model of tendon injury is reproducible and suitable for quantitative histological analysis. Tendons analysed at day 1, 3, 5, 7 and 14 after wounding demonstrated a well-demarcated "acellular zone" around the suture within 24 hours and persisting over 14 days. The placement of an untied suture in tendon did not produce this effect but tying and releasing the tied knot did. The rapidity of onset suggests that cells move from the zone of injury into less mechanically strained tissue. The acellular zone was apparent in rabbit hind paw flexor tendon which is vascularised and the corresponding tendon in mouse which has no intrinsic blood vessels. This phenomenon highlights biological events that must be considered in parallel with the current trend for multistrand locking flexor tendon suture repairs.

Whole-leg duplex mapping for varicose veins: observations on patterns of reflux in recurrent and primary legs, with clinical correlation.

BACKGROUND: the variability of venous reflux patterns complicate the management of venous disease. Our study investigates specific variations in venous anatomy and patterns of reflux in varying clinical situations. METHODS: prospective analysis of 464 legs in 355 patients was performed by complete duplex venous mapping of both primary and recurrent varicose veins. Hand Held Doppler (HHD) and Duplex Ultrasonography (Duplex US) observations in the popliteal fossa were compared in a subgroup of 89 patients with primary varicose veins. Distribution of venous system disease was correlated with clinical severity in a subgroup of 117 affected legs which was representative of the overall study group. RESULTS: sapheno-femoral junction (SFJ) incompetence predominated in both primary and recurrent varicose veins. Only 21% of primary legs and 25% of recurrent legs had sapheno-popliteal junction (SPJ) incompetence. SPJ incompetence was present in only 42% of cases where reflux in the popliteal region on HHD had been demonstrated. A proportion of both primary and recurrent varicose veins had evidence of deep venous incompetence (DVI). Sixty-four percent of primary leg ulcer patients had superficial incompetence alone. In patients with recurrent varicosities and ulceration, 57% had SPJ incompetence, 64% multiple sites and 50% DVI. CONCLUSION: the complex variations of varicose vein anatomy and functional pathology in the lower limb are currently best assessed by complete whole-leg venous duplex mapping.