Sex differences in ACL loading and strain during typical athletic movements: a musculoskeletal simulation analysis.

PURPOSE: Female athletes experience anterior cruciate ligament (ACL) injuries at a much greater rate than males, yet the mechanisms responsible for this are not well-understood. The current investigation aimed using a musculoskeletal simulation-based approach, to examine sex differences in ACL loading parameters during cut and hop movements. METHODS: Fifteen male and fifteen female participants completed 45° cut and maximal one legged hop movements. Three-dimensional motion capture and ground reaction force data during the stance phase of the cut movement and landing phase of the one legged hop were obtained. Lower extremity muscle forces, ACL forces and ACL strains were extracted via a simulation-based approach using a musculoskeletal model, with an ACL insertion into the femur and tibia. RESULTS: During the hop movement, females were associated with significantly greater peak ACL forces (male = 15.01 N/kg and female = 15.70 N/kg) and strains (male = 6.87% and female = 10.74%). In addition, for both the cut (male = 4.45 and female = 1.45) and hop (male = 2.04 and female = 1.46) movements, the soleus/gastrocnemius ratio was significantly larger in males. CONCLUSIONS: The current investigation provides new information regarding sex differences during athletic movements that provide further insight regarding the increased incidence of ACL injuries in females.

Effects training in hypoxia on cardiometabolic parameters in obese people: A systematic review of randomized controlled trial.

OBJECTIVE: The aim of the present review is to evaluate effects of intermittent hypoxia and exercise therapy in cardiometabolic parameters on adult obese people. DATABASE: Three well-known databases were selected: EMBASE, MEDLINE and Web of Science. Studies selection: Inclusion criteria were: (a) human healthy overweight or obese adults, (b) study randomized controlled trial, (c) original experimental study, (d) English languages and (e) therapy with intermittent hypoxia and exercise. DESIGN: The assessment of the methodological quality of each study was based upon the risk of bias (PEDro scale) and level of evidence (CBO Guidelines). DATA EXTRACTION: five articles clearly met inclusion criteria and were reviewed to data extraction. RESULTS: In the hypoxia groups, weight, body mass index, waist circumference, waist-hip ratio, fat mass and lean mass improved in at least two studies in comparison with the baseline. Systolic blood pressure improved in one study. The lipid profile and the aerobic capacity were not reduced significantly. CONCLUSIONS: Results suggest that combined hypoxia with exercise may help to improve cardiometabolic parameters in obese people.

Electromyographic response of global abdominal stabilizers in response to stable- and unstable-base isometric exercise.

Core stability training traditionally uses stable-base techniques. Less is known as to the use of unstable-base techniques, such as suspension training, to activate core musculature. This study sought to assess the neuromuscular activation of global core stabilizers when using suspension training techniques, compared with more traditional forms of isometric exercise. Eighteen elite level, male youth swimmers (age, 15.5 ± 2.3 years; stature, 163.3 ± 12.7 cm; body mass, 62.2 ± 11.9 kg) participated in this study. Surface electromyography (sEMG) was used to determine the rate of muscle contraction in postural musculature, associated with core stability and torso bracing (rectus abdominus [RA], external obliques [EO], erector spinae [ES]). A maximal voluntary contraction test was used to determine peak amplitude for all muscles. Static bracing of the core was achieved using a modified "plank" position, with and without a Swiss ball, and held for 30 seconds. A mechanically similar "plank" was then held using suspension straps. Analysis of sEMG revealed that suspension produced higher peak amplitude in the RA than using a prone or Swiss ball "plank" (p = 0.04). This difference was not replicated in either the EO or ES musculature. We conclude that suspension training noticeably improves engagement of anterior core musculature when compared with both lateral and posterior muscles. Further research is required to determine how best to activate both posterior and lateral musculature when using all forms of core stability training.

Three-dimensional kinematic comparison of treadmill and overground running.

The treadmill is an attractive device for the investigation of human locomotion, yet the extent to which lower limb kinematics differ from overground running remains a controversial topic. This study aimed to provide an extensive three-dimensional kinematic comparison of the lower extremities during overground and treadmill running. Twelve participants ran at 4.0 m/s (+/- 5%) in both treadmill and overground conditions. Angular kinematic parameters of the lower extremities during the stance phase were collected at 250 Hz using an eight-camera motion analysis system. Hip, knee, and ankle joint kinematics were quantified in the sagittal, coronal, and transverse planes, and contrasted using paired t-tests. Of the analysed parameters hip flexion at footstrike and ankle excursion to peak angle were found to be significantly reduced during treadmill running by 12 degrees (p = 0.001) and 6.6 degrees (p = 0.010), respectively. Treadmill running was found to be associated with significantly greater peak ankle eversion (by 6.3 degrees, p = 0.006). It was concluded that the mechanics of treadmill running cannot be generalized to overground running.

The utility of multimedia in the diagnosis and management of acute and subacute problems in hand surgery.

A typical consultation is based on a phone conversation between the consulting service and the surgeon. If the description given to the surgeon misrepresents the severity of the condition, unnecessary transfer of the patient could follow. In an attempt to reduce the occurrence of unnecessary transfers, we started supplementing our consultation with video captured with a cell phone camera demonstrating specific points in clinical examination of the hand. These videos were sent to the surgeon to clarify the clinical picture. We found this method useful in some cases in ruling out the need for urgent transfer.

Functional outcome following nerve repair in the upper extremity using processed nerve allograft.

PURPOSE: Reconstruction of peripheral nerve discontinuities with processed nerve allograft has become increasingly relevant. The RANGER Study registry was initiated in 2007 to study the use of processed nerve allografts in contemporary clinical practice. We undertook this study to analyze outcomes for upper extremity nerve repairs contained in the registry database. METHODS: We identified an upper extremity-specific population within the RANGER Study registry database consisting of 71 nerves repaired with processed nerve allograft. This group was composed of 56 subjects with a mean age of 40 ± 17 years (range, 18-86 y). We analyzed data to determine the safety and efficacy of processed nerve allograft. Quantitative data were available on 51 subjects with 35 sensory, 13 mixed, and 3 motor nerves. The mean gap length was 23 ± 12 mm (range, 5-50 mm). We performed an analysis to evaluate response-to-treatment and to examine sensory and motor recovery according to the international standards for motor and sensory nerve recovery. RESULTS: There were no reported implant complications, tissue rejections, or adverse experiences related to the use of the processed nerve allografts. Overall recovery, S3 or M4 and above, was achieved in 86% of the procedures. Subgroup analysis demonstrated meaningful levels of recovery in sensory, mixed, and motor nerve repairs with graft lengths between 5 and 50 mm. The study also found meaningful levels of recovery in 89% of digital nerve repairs, 75% of median nerve repairs, and 67% of ulnar nerve repairs. CONCLUSIONS: Our data suggest that processed nerve allografts offer a safe and effective method of reconstructing peripheral nerve gaps from 5 to 50 mm in length. These outcomes compare favorably with those reported in the literature for nerve autograft, and exceed those reported for tube conduits.

Microvascular approach to scalp replantation and reconstruction: a thirty-six year experience.

BACKGROUND: Soft tissue defects of the scalp may result from multiple etiologies and can be challenging to reconstruct. We discuss our experience with scalp replantation and secondary microvascular reconstruction over 36 years, including techniques pioneered at our institution with twin-twin scalp allotransplant and innervated partial superior latissimus dorsi (LD) for scalp/frontalis loss. METHODS: A retrospective review of all patients presenting with scalp loss requiring microvascular reconstruction at a single center was performed from January 1971 to January 2007. Medical records were reviewed for age, gender, defect size/location, etiology, type of reconstruction, recipient vessels used, vein grafts, and complications. RESULTS: Thirty-three patients were identified; mean age was 33 years (range, 7-79). Mean scalp defect size was 442 cm(2) (range, 120-900 cm(2)). Thirty-six microvascular reconstructions were performed; of these, 10 scalp replants and 26 microvascular tissue transfers. Of these 26, 17 were LD based (partial superior LD with and without reinnervation, LD combined with serratus, LD combined with parascapular, LD combined with split rib, LD only) and 2 free scalp allotransplant among others. The superficial temporal artery and vein was used as recipient vessels in 70% of cases. Overall, microvascular success rate was 92%; complications occurred in 14 cases, nine major (tumor recurrence [n = 2], partial flap loss [n = 2], replant loss [n = 3, size <300 cm(2) ], hematoma [n = 2]) and five minor (donor site seroma /hematoma [n = 3], flap congestion [n = 1], superficial wound infection [n = 1]). CONCLUSIONS: Every attempt should be made at scalp replantation when the patient is stable and the parts salvageable. Larger avulsion defects had higher success rates after replantation than smaller defects (<300 cm(2) ), with the superficial temporal artery and vein most commonly used for recipient vessels (P = 0.0083). Microvascular tissue transfer remains a mainstay of treatment for scalp defects, with LD-based flaps, demonstrating excellent versatility for a range of defects.

A multi-disciplinary approach to the management of fungal osteomyelitis: current concepts in post-traumatic lower extremity reconstruction: a case report.

Limb salvage in fungal osteomyelitis of the post-traumatic lower extremity represents a difficult clinical problem requiring aggressive management. We report lower extremity salvage by radical bony debridement, free tissue transfer, distraction osteogenesis with bone-docking, and a novel antifungal regimen in a clinical setting of infection with Scedosporium inflatum, historically requiring amputation in 100% of cases. We treated Scedosporium inflatum osteomyelitis of the tibia and calcaneus with radical debridement of infected bone, free partial medial rectus abdominis muscle flap coverage, transport distraction osteogenesis, and combination voriconazole/terbinafine chemotherapy, a novel antifungal regimen. We achieved successful control of the infection, limb salvage, and an excellent functional outcome through aggressive debridement of infected bone and soft tissue, elimination of dead space within the bony defect, the robust perfusion provided by the free flap, the hypervascular state induced by distraction osteogenesis, and the synergism of the novel antifungal regimen.

Processed nerve allografts for peripheral nerve reconstruction: a multicenter study of utilization and outcomes in sensory, mixed, and motor nerve reconstructions.

PURPOSE: As alternatives to autograft become more conventional, clinical outcomes data on their effectiveness in restoring meaningful function is essential. In this study we report on the outcomes from a multicenter study on processed nerve allografts (Avance® Nerve Graft, AxoGen, Inc). PATIENTS AND METHODS: Twelve sites with 25 surgeons contributed data from 132 individual nerve injuries. Data was analyzed to determine the safety and efficacy of the nerve allograft. Sufficient data for efficacy analysis were reported in 76 injuries (49 sensory, 18 mixed, and 9 motor nerves). The mean age was 41 ± 17 (18-86) years. The mean graft length was 22 ± 11 (5-50) mm. Subgroup analysis was performed to determine the relationship to factors known to influence outcomes of nerve repair such as nerve type, gap length, patient age, time to repair, age of injury, and mechanism of injury. RESULTS: Meaningful recovery was reported in 87% of the repairs reporting quantitative data. Subgroup analysis demonstrated consistency, showing no significant differences with regard to recovery outcomes between the groups (P > 0.05 Fisher's Exact Test). No graft related adverse experiences were reported and a 5% revision rate was observed. CONCLUSION: Processed nerve allografts performed well and were found to be safe and effective in sensory, mixed and motor nerve defects between 5 and 50 mm. The outcomes for safety and meaningful recovery observed in this study compare favorably to those reported in the literature for nerve autograft and are higher than those reported for nerve conduits.

Artery-vein-artery venous flap for simultaneous soft-tissue repair and radial artery reconstruction: case report.

We present a case of partial amputation of the forearm resulting in soft-tissue and radial artery defects that were simultaneously repaired using a large artery-vein-artery venous flap. The flap measured 4 × 11 cm, and we attribute its complete survival and long-term durability to the artery-vein-artery configuration.

Standardized protocol for artery-only fingertip replantation.

PURPOSE: Artery-only fingertip replantation can be reliable if low-resistance flow through the replant is maintained until venous outflow is restored naturally. Injuring the tip of the replant to promote ongoing bleeding augmented with anticoagulation usually accomplishes this; however, such management results in prolonged hospitalization. In this study, we analyzed the outcomes of artery-only fingertip replantation using a standardized postoperative protocol consisting of dextran-40, heparin, and leech therapy. METHODS: Between 2001 and 2008, we performed 19 artery-only fingertip replants for 17 patients. All patients had the replanted nail plate removed and received intravenous dextran-40, heparin, and aspirin to promote fingertip bleeding and vascular outflow. Anticoagulation was titrated to promote a controlled bleed until physiologic venous outflow was restored by neovascularization. We used medicinal leeches and mechanical heparin scrubbing for acute decongestion. By postoperative day 6, bleeding was no longer promoted. We initiated fluorescent dye perfusion studies to assess circulatory competence and direct further anticoagulant intervention if necessary. The absence of bleeding associated with an initial rise followed by an appropriate fall in fluorescent dye concentration would trigger a weaning of anticoagulation. RESULTS: All of the 19 replants survived. The average length of hospital stay was 9 days (range, 7-17 d). Eleven patients received blood transfusions. The average transfusion was 1.8 units (range, 0-9 units). All patients were happy with the decision to replant, and the cosmetic result. CONCLUSIONS: A protocol that promotes temporary, controlled bleeding from the fingertip is protective of artery-only replants distal to the distal interphalangeal joint until physiologic venous outflow is restored. The protocol described is both safe and reliable. The patient should be informed that such replant attempts may result in the need for transfusions and extended hospital stays, factors that can help the physician and patient decide whether to proceed with replantation. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Selected outcomes of thumb replantation after isolated thumb amputation injury.

PURPOSE: The aim of this study was to assess thumb survival, pinch strength, grip strength, and need for secondary surgery in patients undergoing thumb replantation after isolated thumb amputation injury. METHODS: We conducted a retrospective review of 52 consecutive isolated thumb replantations performed over a 4.5-year period. Charts were reviewed for mechanism of injury, level of amputation, and surgical technique. Primary outcomes of interest included survival and secondary surgery (eg, tenolysis, neurolysis) rates. Functional outcome was assessed by pinch and grip strengths after a mean follow-up period of 10 months from the initial injury. RESULTS: The overall thumb survival rate was 92% (48 of 52). One hundred percent of Zone I injuries (13 of 13), 94% of zone II injuries (29 of 31), and 75% of zone III injuries (6 of 8) survived; overall survival was 94% in sharp injuries (32 of 34), 89% in avulsion injuries (8 of 9), and 89% in crush injuries (8 of 9). Secondary surgery was performed in 18 patients with increasing need across the 3 zones (0%, 42%, and 63%, respectively; p for trend = .002). Pinch and grip strengths of 17 patients after an average follow-up period of 10 months were significantly worse after crush/avulsion injuries (p = .007 and .07, respectively) and injuries requiring joint intervention (p = .004 and .02, respectively); grip strength was also found to be negatively associated with increasing zone of injury. CONCLUSIONS: This retrospective study shows that a high rate of survival can be achieved after thumb replantation using current techniques. In addition, the need for secondary surgery is strongly related to zone of injury, with zone I injuries requiring the least amount of secondary surgery. Finally, pinch and grip strengths may be worse after crush or avulsion injuries and injuries requiring joint intervention. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Arterialized venous flaps: a review of the literature.

The arterialized venous flaps are highly regarded in microsurgical and reconstructive surgeries based on advantages of ease of design and harvest without the need to perform deep dissection, no sacrifice of a major artery at the donor site, no limitation of the donor sites, and less donor-site morbidity. Many experimental investigations and clinical applications have been reported. However, their survivals are still inconsistent, and survival mechanisms remain controversial. In this review, we update the existing problems, experimental studies for survival mechanisms, clinical practices, and methods developed to improve their survivals.

Improvement of prearterialized venous flap survival with delay procedure in rats.

The purpose of this experimental study is to investigate the improvement in flap survival of prearterialization with delay procedure in venous flaps in rats. The transverse superficial inferior epigastric flap was utilized. Forty-six rats were randomized into four groups: group 1 as arterialized venous flaps, group 2 as venous flaps of prearterialization with delay procedure, group 3 as arterial perfusion venous flap, and group 4 as venous perfusion venous flap. Direct observation, histological analysis, and vascular perfusion examination by Indian ink injection were performed for flap assessment. The percentage of flap survival was 41.6 +/- 2.4%, 98.0 +/- 1.8%, 89.5 +/- 1.0%, and 11.3 +/- 0.8% in these four groups, respectively. Significant differences were noted between groups ( P < 0.05) except for between group 2 and group 3 ( P > 0.05). Vascular perfusion studies revealed that the Indian ink filled the entire flaps of group 2 in comparison with partially filled flaps in other groups. Histological examination showed more small vessels were observed through all layers of the flaps as well as dilated superficial veins in group 2 than those in other groups. In conclusion, prearterialization with delay procedure can improve the viability of the flap, and this method may be a strategy for flap prefabrication based on the venous network.

Bilateral breast reconstruction: the simultaneous use of autogenous tissue and identical twin isograft.

Not all patients seeking autogenous breast reconstruction have sufficient donor tissue for a bilateral reconstruction. Identical twin isotransplantation, as a model system for allotransplantation without immunologic barriers, broadens the definition of "spare parts" surgery. In this case, we demonstrate the simultaneous transplantation of both autogenous and syngeneic deep inferior epigastric perforator flaps for bilateral breast reconstruction. As our understanding of immunology evolves, allotransplantation may further increase our reconstructive options for other postmastectomy patients.

Resurfacing of a complex upper extremity injury: an excellent indication for the dorsal thoracic fascial flap.

We report a case of a 24-year-old patient who sustained a mutilating crush injury to the left forearm. After thorough debridement and stabilization of the skeletal injury, the dorsal thoracic fascial flap was used to resurface the circumferential wound, protect the underlying structures, and provide a gliding surface for the exposed tendons. The flap was safely transected during revision surgery, and at 6-months follow-up, excellent functional and cosmetic results were achieved. The dorsal thoracic fascia is a thin, durable, and pliable tissue that is based on a long vascular pedicle. We consider the dorsal thoracic fascial flap as a valuable option for coverage of complex upper extremity injuries and highly recommend its use.

Microsurgical scalp reconstruction after a mountain lion attack.

Mountain lion attacks on humans are rare and potentially fatal. Although few victims experience minor injuries, permanent disfigurement and disability is common among survivors of these assaults. Since 1986, a steady number of mountain lion attacks have been noted in California. We report a recent attack of a cougar on a couple hiking in California's Prairie Creek Redwoods State Park. The victim sustained a significant scalp injury that led to a life-threatening soft-tissue infection. We present an analysis of the injury pattern as it relates to the bite marks, the resulting degloving injury, and the surgical reconstruction. We also offer a current survey of the pathogens often found in cats' and mountain lions' bite wounds and the appropriate antibiotic treatment. Given the infrequency at which clinicians encounter mountain lion injuries, we recommend that after initial management and exclusion of life threatening injuries patients be transferred to a tertiary care facility capable of managing the various reconstructive challenges such as the one presented in this case.

Partial muscle harvest: our first 100 cases attempting to preserve form and function at the donor site.

The authors report their first 100 partial muscle flaps as a strategy to preserve form and function of the donor site in muscle transplantation. Between 2003 and 2007, 62 partial superior latissimus (PSL) flaps and 38 partial medial rectus (PMR) flaps were transplanted for head and neck, upper and lower extremity, and chest wall reconstruction. All flaps survived. There were hematomas at the donor sites in two PMR cases. Form and function were preserved at the donor site in all cases. The PSL provided comparable muscle volume and pedicle length to the entire rectus abdominis muscle. An additional benefit was its use as a functional muscle. The PMR flap provided comparable muscle volume to the gracilis muscle. An additional benefit was a much longer vascular pedicle. Small to moderate sized flaps can be harvested from the fabric of the latissimus dorsi and rectus abdomenis muscles and be reliably transplanted. When positioned at the superior edge of the latissimus or medial edge of the rectus muscle, adequate blood flow and innervation to the residual muscle result in preservation of form and function at the donor site. The benefits of muscle transplantation can be realized without the associated morbidity of muscle harvest.

Use of the venous flap for salvage of difficult ring avulsion injuries.

Ring avulsion can lead to soft tissue compromise resulting in eventual digit failure or restriction of motion. The authors present use of the venous flow through flap for simultaneous soft tissue and digital vessel reconstruction in severe ring avulsion injury. A retrospective review of ring avulsion injuries treated with transplantation of an arterialized (A-V-A) venous flap between 1999 and 2006 was conducted. Indications included digits which were debrided and required soft tissue and digital artery reconstruction. Eight venous flaps were transplanted for 3 Urbaniak class II and 5 Urbaniak class III ring avulsions. Average size of the venous flap was 6 cm(2). All flaps and digits survived without partial necrosis. The soft tissue envelope was supple in all cases. Total active motion (TAM) ranged from 160 to 210 degrees. The arterialized venous flow-through flap is a reliable solution for the complex ring avulsion injury which requires simultaneous soft tissue and digital vessel reconstruction.

Index finger salvage with replantation and revascularization: revisiting conventional wisdom.

Replantation/revascularization of severely injured single digits is controversial, especially at the index position. Conventional wisdom is that these digits if salvaged will ultimately worsen residual hand function and they should be amputated. Twenty-eight cases of such index salvages were reviewed to test this hypothesis. Five cases involved children and were excluded. Twenty-three replants/revascularizations survived (100%). Total active motion was 170 degrees in zone 1, and 133 degrees for zone 2 injuries. Patient satisfaction was high in all cases. In selected cases, salvage of severely injured and amputated index fingers has the potential for satisfying survival and functional results and dogmatic treatment with completion amputation should be avoided.