Hand injuries during COVID-19: Lessons from lockdown.

The two-month nationwide lockdown implemented in Australia in response to COVID-19 involved restrictions on social gatherings and non-essential services, resulting in marked changes to the distribution of time spent at home and in the workplace. Given the likelihood of future lockdowns, this study aimed to investigate whether the lockdown was associated with an alteration in the pattern of acute hand injuries admitted to Sydney Hospital Hand Unit relative to the same period in 2019, and whether target areas for preventative strategies could be identified. During the lockdown period in 2020, 332 acute presentations were noted, and in the same period in 2019, 310 cases were noted.

Structural Failure Mechanisms of Common Flexor Tendon Repairs.

Background: This study investigated the exact failure mechanisms of the most commonly used conventional tendon repair techniques. A new method, radiographing repair constructs in antero-posterior and lateral projections before and after tensioning was used. This allowed to precisely analyse failure mechanisms in regards to geometrical changes in all three dimensions.

Tendon to bone healing and its implications for surgery.

Entheses are complex structures which act to reduce stress concentrations between tendon and skeleton tissues. Understanding the development and function of the enthesis organ has implications for surgical repair, particularly in regards to healing and the regulation of tendon to bone engraftment. In this paper we review the development and function of entheses as well as the enthesis organ concept.

Etonogestrel implants - case studies of median nerve injury following removal.

The etonogestrel implant has been available in Australia since 2001. General practitioners routinely insert and remove these implants in their rooms under local anaesthetic. We report two cases of significant median nerve injury following inappropriate dissection of the arm to remove this device when impalpable.

Influence of locking stitch size in a four-strand cross-locked cruciate flexor tendon repair.

Purpose: The 4-strand cross-locked cruciate technique (Adelaide technique) for repairing flexor tendons in zone II is a favorable method in terms of strength and simplicity. The purpose of this study was to investigate the effects of varying the cross-lock stitch size in this repair technique. Outcomes measured were load to failure and gap formation.

The relationship between gap formation and grip-to-grip displacement during cyclic testing of repaired flexor tendons.

The assessment of repair site gap formation during cyclic loading of reconstructed flexor tendons provides important data on the performance of repair techniques in the early postoperative period. This study describes our cyclic testing protocol and evaluates the relationship between changes in optical gap and grip-to-grip displacement. Sixteen sheep hind limb deep flexor tendons were randomized into four repair groups (n=4 per group): a 2-strand repair (modified Kessler) and 4-strand repair (Adelaide), both with and without a simple running peripheral suture.

A model of pressure distribution under peripherally secured foam dressings on a convex surface: does this contribute to skin graft loss?

Background: Successful skin grafting requires multiple factors for success. An even distribution of constant pressure exerted upon the graft is necessary for successful graft take. It is well known that excessive pressure on a graft causes ischemia and may result in the failure of graft take.

A biomechanical assessment of repair versus nonrepair of sheep flexor tendons lacerated to 75 percent.

Purpose: The benefit of repairing a 75% partial flexor tendon laceration remains controversial. The purpose of this study was to assess the degree of gap formation with and without repair when the 75% lacerated tendon is subjected to cyclic loading. Repair with only a peripheral suture was compared to that using a core and peripheral repair technique.

In vitro comparison of lagged and nonlagged screw fixation of metacarpal fractures in cadavers.

Purpose: Lag screw fixation is reported to provide the most biomechanically stable construct for fixation of oblique or spiral metacarpal fractures. Lag screws are inserted after overdrilling the proximal cortex, resulting in compression at the fracture site. Minor drilling errors can result in poor screw purchase, instability, and ultimately impaired fracture healing.

Pediatric treadmill injuries: a public health issue.

Background: Treadmill injuries in children tend to be severe and are becoming increasingly common. We present an overview of this problem to promote public awareness, education, and to advocate a prevention strategy for this preventable injury.

Methods: Medical records of all children with treadmill-related injuries during a 6-year period (January 2001-November 2006) from 2 tertiary pediatric hospitals were reviewed.

Growth factor expression following clinical mandibular distraction osteogenesis in humans and its comparison with existing animal studies.

Aim: Lengthening the mandible by distraction osteogenesis (DO) is nowadays a well recognized technique in maxillofacial surgery. In this study growth factor expression profiles were examined in biopsies taken from six patients undergoing mandibular DO and compared with findings from a sheep model for mandibular DO.

Study Design: In all patients (and sheep), the ascending ramus was distracted 10-15 mm at a rate of 1mm/day using an intraoral device.

The effect of rate of distraction osteogenesis on structure and function of anterior digastric muscle fibers.

The authors hypothesized that distraction at a rate of 3 mm/day, compared with mandibular distraction at a rate of 1 mm/day, would produce a maladaptive response in adjacent muscles of mastication. The authors further hypothesized that the maladaptive response would manifest at the single fiber level by means of increased sarcomeric heterogeneity, decreased maximum force output, and increased susceptibility to stretch-induced injury. In an ovine model, distraction osteogenesis of the right hemimandible was performed at either 1 mm/day for 21 days (n = 2) or 3 mm/day for 7 days (n = 2) to achieve a total distraction distance of 21 mm.

The role of nerve growth factor and brain-derived neurotrophic factor in inferior alveolar nerve regeneration in distraction osteogenesis.

Distraction osteogenesis (DO) has become the mainstay of treatment of mandibular hypoplasias. Despite the clinical acceptance of the technique in the last decade, little is known of the biological mechanism of bone and soft tissue regeneration. The biological response of peripheral nerves to distraction has not been well documented.