D. Nicole Deal

Ice reduces edema. A study of microvascular permeability in rats.

Background: Ice is applied following a soft-tissue injury on the basis of clinical information. This study investigates the relationship between ice therapy (cryotherapy) and edema by determining microvascular permeability before and after contusion with and without ice therapy and provides data supporting a reduction in edema following cryotherapy.Methods: A dorsal microvascular chamber was created in rats to allow the direct examination of microvascular parameters in intact, pre-established microvascular beds of the cutaneous maximus muscle in conscious rats. The rats received a contusion or sham contusion and were treated with cryotherapy or were not treated. Microvascular permeability (edema) was assessed by measuring fluorescent-labeled albumin in the interstitial fluid before and after contusion.Results: Microvascular permeability following contusion was significantly increased in the group that received the contusion without cryotherapy compared with that in the group that received the sham contusion without cryotherapy (control) (p < 0.001). When ice was applied fifteen minutes after the contusion for twenty minutes, microvascular permeability (edema) decreased significantly (p < 0.001) compared with that in the group that did not receive cryotherapy after contusion. Permeability was increased in the group that received cryotherapy following the contusion compared with that in the control group (p = 0.012), although the increase was not as great as that between the group that received the contusion without cryotherapy and the control group. Sham contusion with cryotherapy significantly reduced microvascular permeability compared with that in the control group (p = 0.004). Sham contusion without cryotherapy did not cause a significant change in the microvascular permeability of postcapillary venules after 300 minutes compared with baseline measurements.Conclusions: The application of ice significantly decreased microvascular permeability following striated muscle contusion. The results of this study demonstrated that microvascular permeability is increased following a contusion coincident with significant leukocyte-endothelial interactions. However, microvascular permeability was significantly reduced following cryotherapy, a treatment demonstrated to reduce the number of rolling and adherent leukocytes. This association suggests that the reduction in edema in injured skeletal muscle following cryotherapy may be due to a reduction in leukocyte-endothelial interactions.Clinical Relevance: This study provides scientific data to support the clinical observation that ice reduces edema.

Peripheral nerve repair and reconstruction.

When possible, direct repair remains the current standard of care for the repair of peripheral nerve lacerations. In large nerve gaps, in which direct repair is not possible, grafting remains the most viable option. Nerve scaffolds include autologous conduits, artificial nonbioabsorbable conduits, and bioabsorbable conduits and are options for repair of digital nerve gaps that are <3 cm in length. Experimental studies suggest that the use of allografts may be an option for repairing larger sensory nerve gaps without associated donor-site morbidity.

High-Pressure Injection Injuries

EFINITION igh-pressure injection injuries occur when equipment apable of achieving pressures sufficient to breach the uman skin injects its contents into the human body, ost commonly into the hand. The pressure required to penetrate intact human skin is commonly cited at 7 bar (7 10 N/m) or 100 psi. A careful review of that eference provides no source or justification for the umber. Nevertheless, oddly, it is cited by multiple uthors.

Management of peripheral nerve defects: External fixator-assisted primary neurorrhaphy

BACKGROUND Controlled joint extension followed by gradual distraction with use of an external fixator may facilitate primary repair of peripheral nerve defects by permitting end-to-end repair without tension. The hypothesis of the present study was that gradual lengthening of nerve repairs with use of incremental distraction would provide superior results compared with grafting or repair under tension. METHODS A median nerve segment measuring four times the diameter of the nerve was resected in thirty-six rabbits to create a 7-mm gap in the nerve. Neurorrhaphy was performed with use of one of three techniques. In Group 1 (cable graft), a tension-free medial antebrachial cutaneous graft was placed to allow full range of motion of the elbow postoperatively. In Group 2 (end-to-end repair without distraction), the elbow was externally fixed in hyperflexion and the nerve was repaired end-to-end. At fourteen days, the fixator was removed and unprotected elbow motion was permitted. In Group 3 (end-to-end repair with gradual distraction), the elbow was externally fixed in hyperflexion and primary neurorrhaphy was performed. At fourteen days, the elbow was extended 10 degrees every other day with use of the articulated external fixator until full extension was achieved. Median nerve amplitude, latency, and nerve-conduction velocity; flexor digitorum superficialis single-twitch force generation and maximum tetanic force generation; muscle mass; and elbow range of motion were measured at three or six months. In addition, histologic analysis of the median nerve distal to the repair site and the morphometry of the neuromuscular junction in the flexor digitorum superficialis were performed at six months. RESULTS All rabbits regained full active and passive range of motion. At three months, the nerve-conduction velocities in Groups 2 and 3 were significantly greater than that in Group 1. At six months, the nerve-conduction velocities and amplitudes in Group 3 were significantly greater than those in Groups 1 and 2. At six months, the tetanic force in Group 3 was significantly greater than those in Groups 1 and 2. There were no significant differences in muscle mass among the groups. There were no significant differences in histological findings among the three groups, although there was a trend toward larger fiber size in Group 3 as compared with the other two groups. The neuromuscular junctions in Group 3 had a significantly larger surface area than did those in Group 1 (p = 0.002) and Group 2 (p = 0.034). CONCLUSION The use of an articulated external fixator and controlled gradual distraction appears to facilitate the treatment of peripheral nerve defects.

Distal Ulna Fractures

In isolation, distal ulna fractures are rare. They are often found in conjunction with distal radius fractures, and the complexity of the interaction of the distal ulna with the radioulnar joint and triangular fibrocartilage complex makes understanding and treatment of distal ulna fractures challenging. Fixation of distal ulna fractures can be problematic owing to comminution making reduction challenging. A thin soft tissue can lead to hardware prominence and necessitate implant removal. In this Current Concepts article, we review the anatomy, pathology, and treatment of distal ulna fractures as well as potential complications and salvage procedures.

Soft-tissue coverage of complex dorsal hand and finger defects using the turnover adipofascial flap.

Complex hand wounds with exposed tendon or bone often require free tissue transfer. We report results in 13 patients with complex dorsal hand or digital wounds who underwent soft-tissue reconstruction using a turnover adipofascial flap and skin grafting over a 35-month period. The mean patient age was 44 years. Mechanism of injury included the following: three gunshot, four degloving, one table saw, three chain saw, one thumb avulsion, and one crush. Flap sizes varied from 2 × 4 to 10 × 18 cm, involving the dorsum of the hand in four patients, thumb in two patients, index finger in one patient, long finger in three patients, long and ring fingers in one patient, and web space in two patients. Skin graft survival was 100% in 12 patients. One patient died of sepsis from unrelated medical conditions. All fractures were healed at follow-up, and there were no donor site complications. The adipofascial flap is a good alternative to free tissue transfer for the coverage of complex dorsal hand and finger soft-tissue defects and is associated with technical ease, good cosmetic results, and minimal donor site morbidity.

Diagnosis and Management of the Acute Felon: Evidence-Based Review

THE PATIENT A 52-year-old, right-handed man with diabetes presents with a 2-day history of worsening pain and swelling in the pulp of his left index fingertip. Examination in the emergency department revealed the patient to be afebrile, with point tenderness and erythema over the pulp of his distal left index finger. The remainder of the finger was without erythema or swelling, and there was no tenderness along the flexor tendon sheath. The finger was neurovascularly intact, and radiographs were negative for foreign body or osteomyelitis.

Neuromuscular recovery after distraction osteogenesis at different frequencies in a rabbit model.

Abstract: The muscle and nerve responses to stresses applied during distraction osteogenesis have not been clearly defined. This study hypothesized that distraction resulting in 30% lengthening decreases muscle force generation of the lengthened muscle and increasing the frequency of distraction attenuates the decrease of force generation accompanying lengthening. This study investigated the effects of different distraction frequencies on neuromuscular recovery in a rabbit model. Animals were assigned into group 1 (low-frequency distraction) and group 2 (high-frequency distraction). Distraction was continued until a 30% increase in the original tibial length was achieved. After consolidation of the osteotomy, knee and ankle range of motion, muscle force generation, and neuromuscular junction parameters were evaluated. Lengthening of 30% resulted in significantly decreased range of motion compared with the control leg (P < 0.05). Lengthening of 30% also substantially decreased force generation of the peroneus longus muscle. However, force generation of the peroneus longus muscle in the high-frequency group was 70.5% ± 6.5% of the control side, significantly higher than that in the low-frequency distraction group (49.7% ± 4.8% of the control side, P < 0.05). There was no statistical difference between the 2 groups in neuromuscular junction morphology, although an abnormal shape of the postsynaptic neuromuscular junction was observed after distraction. The use of a high-frequency distraction technique during limb lengthening may result in a reduction in impairment of knee and ankle range of motion and improved muscle function compared with that observed with the use of low-frequency distraction. Repeated microtrauma to the soft tissues associated with high-frequency distraction may facilitate the regenerative capacity of the soft tissues and result in an improved outcome of muscle and nerve function.

Fibromyalgia as a Predictor of Complex Regional Pain Syndrome After Distal Radius Fracture

Background: Complex regional pain syndrome (CRPS) can be a devastating complication following extremity injury, but risk factors are not well understood. The purpose of this study was to investigate the association between fibromyalgia and the development of CRPS after distal radius fracture. Methods: The PearlDiver Medicare database was queried using International Classification of Diseases, 9th Revision (ICD-9) and Current Procedural Terminology (CPT) codes for diagnoses and treatments of distal radius fractures. Patients were separated into fibromyalgia and control cohorts, and the prevalence of CRPS was measured at 3, 6, 9, and 12 months from the date of injury or procedure. Demographic factors, treatment modality, and comorbid conditions were analyzed by multivariable logistic regression to reduce confounding and identify additional risk factors. Results: Database queries yielded 853 186 patients diagnosed or treated for distal radius fracture, with 6% having previous diagnosis of fibromyalgia. The prevalence of CRPS following distal radius fracture was increased at 3, 6, 9, and 12 months in the fibromyalgia cohort compared with the control c, with a 1-year incidence of 0.51% compared with 0.20% (odds ratio [OR], 2.54, P < .001). Multivariable logistic regression supported the association, with estimated OR of 2.0 (P < .001). In addition, female gender, surgical or manipulative treatment, and anxiety were positively associated with CRPS, and age >65, diabetes, and heart failure were negatively associated. Conclusions: While the basis of the association between fibromyalgia and CRPS is unknown, our data suggest that it could serve as a useful predictor of CRPS risk, promoting increased vigilance for CRPS symptoms and earlier recognition and treatment, thereby improving patient outcomes.

Radial Head Fracture Fixation Using Tripod Technique With Headless Compression Screws

Radial head and neck fractures are one of the most common elbow fractures, comprising 2% to 5% of all fractures, and 30% of elbow fractures. Although uncomplicated Mason type I fractures can be managed nonsurgically, Mason type II-IV fractures require additional intervention. Mason type II-III fractures with 3 or fewer fragments are typically treated with open reduction and internal fixation using 2 to 3 lag screws. Transverse radial neck involvement or axial instability with screw-only fixation has historically required the additional use of a mini fragment T-plate or locking proximal radius plate. More recently, less invasive techniques such as the cross-screw and tripod techniques have been proposed. The purpose of this paper is to detail and demonstrate the proper implementation of the tripod technique using headless compression screws.