bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgeon Practices regarding Operative Treatment of Posterior Malleolus Fractures
Authors: Gardner Michael J. , Streubel Philipp N. , McCormick Jeremy J. , Klein Sandra E. , Johnson Jeffrey E. , Ricci William M.
Published: July 2011

Background:

Operative indications for surgical treatment of posterior malleolar fractures associated with fractures of the distal fibula and tibia are not currently well defined. The purpose of the present study was to determine the current practice among orthopaedic surgeons regarding the management of posterior malleolus fractures.

Materials and Methods:

Web-based questionnaires were emailed to members of the Orthopaedic Trauma Association (OTA) and American Orthopaedic Foot and Ankle Society (AOFAS). Requested information included demographics and treatment preferences for five clinical scenarios with different fracture characteristics. Four hundred one respondents completed the survey (20% response rate). Ninety eight (24%) subjects had received specialty training in orthopaedic trauma, 199 (50%) in foot and ankle (F&A) surgery and six (2%) in both orthopaedic trauma and F&A surgery. Ninety five (24%) had either no or other specialty training.

Results:

The most frequently reported indication for fixation was not based on a fragment size threshold, but rather was “depends on stability and other factors” (56%). Trauma surgeons, those with less than 10 years experience, and those who treated more than five ankles fractures per month were significantly more likely to use factors other than size for indications ( p =0.026,<0.01, and <0.01, respectively). Despite this general response, fragment size still affected treatment decisions. A fragment comprising 50% of the articular surface was indicated for fixation by 97% of respondents, while a size of 10% would be treated by only 9% of respondents. For a posterior fragment with 20% articular involvement and a small free osteochondral fragment, fixation was deemed necessary by 44% of respondents. There were no differences in fellowship training, years of experience in practice, or ankle fracture volume per month in these three situations. A larger proportion of trauma trained surgeons considered fixation necessary compared to F&A trained surgeons in this case ( p=0.028). When posterior malleolus fixation was indicated for a large fragment, direct open reduction using the flexor hallucis longus –peroneal tendon interval was the most commonly selected approach in all cases. Trauma-trained surgeons were significantly more likely to choose antiglide plate fixation compared to screw-only fixation ( p <0.05).

Conclusion:

In this survey study of trauma and F&A surgeons, significant variation existed regarding most aspects of posterior malleolar ankle fracture treatment. Most notably, factors other than fragment size most impacted surgical indications. Newer techniques such as direct exposure and plating of the posterior malleolus are chosen more frequently than traditional techniques of indirect reduction and percutaneous screw fixation. Level of Evidence: IV, Cross-sectional Survey Study
Corticosteroid Injections in the Treatment of Foot & Ankle Disorders: An AOFAS Survey
Authors: Johnson Jeffrey E. , Klein Sandra E. , Putnam Ryan M.
Published: July 2011

Background:

Evidence-based guidelines for the use of injectable corticosteroids are lacking, and the true incidence of complications is unknown.

Materials and Methods:

The 2007–2008 AOFAS membership (969 members) was electronically queried to identify corticosteroid injection practices for certain clinical entities and rates of complications. One hundred ninety-seven surveys were returned. Eleven clinical diagnoses were evaluated for number of injections per year per respondent, rate of injection, plans to change injection pattern, and use of immobilization. Thirteen possible complications were analyzed for observed frequencies and total number of complications.

Results:

Those in practice less than 5 years showed the lowest rate of injections at 14.1 per month, which increased to 26.1 for those in practice 6 to 10 years. An overall average of 20.6 injections per month per clinician was reported. Injections for midsubstance Achilles tendinopathy was largely avoided as demonstrated by a 98% no-inject rate. Insertional Achilles tendonitis was similar, albeit lower with an 88% no-inject rate. Non-Achilles tendonitis showed a varied response for injections. Posterior tibial tendonitis was injected 26% of the time, whereas peroneal tendonitis was injected 54% of the time. Complications including skin depigmentation were observed most frequently (5.1%), followed by atrophy (4%), flare reaction (3.5%), MTPJ dislocation (2.7%), plantar fascia rupture (1.5%), and heel pad atrophy (1.4%).

Conclusion:

Despite many case reports of complications, our survey indicates that the incidence of complications was perceived to be low and generally related to the injection site (skin depigmentation, atrophy, flare reaction).
Surgical Treatment of Advanced Hallux Rigidus by Interpositional Arthroplasty
Authors: Sanhudo Jose A. , Gomes Joao E. , Rodrigo Martini K.
Published: July 2011

Background:

While arthrodesis is the gold-standard for end-stage hallux rigidus, it leads to loss of mobility. The purpose of this paper was to report our clinical results with modified interpositional arthroplasty for the treatment of advanced (Grade III and IV of Coughlin and Shurnas) hallux rigidus.

Material and Methods:

Twenty-five feet with Grade III and IV hallux rigidus underwent cheilectomy, minimal proximal phalanx resection (modified Keller) and interposition of the dorsal capsule and EHB.

Results:

At a minimum followup of 15 months, the mean postoperative hallux AOFAS score was 93.6 points with a pain subscore of 36.4 (maximum, 40 points) and functional subscore of 42.5 (maximum, 45 points). Subjectively, patients were completely satisfied with the surgical outcome in 75% of the cases.

Conclusion:

The modified interpositional arthroplasty was a feasible surgical option to address advanced hallux rigidus in middle aged patients. Level of Evidence: IV, Case Series
Stabilization of Chevron Bunionectomy with a Capsuloperiosteal Flap
Authors: Guclu Berk , Kaya Alper , Akan Burak , Koken Murat , Us Ali Kemal
Published: July 2011

Background:

Distal chevron osteotomy (DCO) for mild to moderate hallux valgus deformity is inherently more stable than the other forms of distal metatarsal osteotomy, but complications such as loss of correction, infection, joint stiffness, delayed union, malunion and nonunion can occur. In this study, we evaluated the use of a capsuloperiosteal flap for stabilization of DCO in the treatment of hallux valgus.

Materials and Methods:

A retrospective study was conducted on 59 patients (88 feet) that underwent distal Chevron osteotomy stabilized only with a capsuloperiosteal flap for mild and moderate hallux valgus deformity with a mean followup of 11.3 years. Clinical evaluation was calculated using the hallux score of the American Orthopaedic Foot and Ankle Society (AOFAS).

Results:

The score improved from a preoperative mean of 52 to a mean of 91.5 points at last followup. Average hallux valgus angle changed from 30.3 degrees preoperatively to 14.2 degrees postoperatively at the last followup. Intermetatarsal angle 1–2 changed from 13.6 degrees preoperatively to 10.2 degrees postoperatively. The correction proved to be consistent with only an average of 3.4-degree correction loss and 4.9-degree loss in the range of motion. Eighty-six feet (97.7%) were pain free. Discomfort with shoewear was absent in 84 feet (95.5%) postoperatively and 24 of 25 (96%) patients were satisfied cosmetically.

Conclusion:

Capsuloperiosteal flap stabilization of distal chevron osteotomy for mild-moderate hallux valgus yielded excellent clinical results at long-term followup.
Analysis of the Proximal Phalanx Size as a Guide for an Akin Closing Wedge Osteotomy
Authors: Shannak Odei , Sehat Khosrow , Dhar Sunil
Published: July 2011

Background:

The Akin closing wedge osteotomy for correction of hallux valgus interphalangeus has experienced a resurgence in popularity. Commonly, the size of the osteotomy is visually judged intraoperatively. We present a means of performing the osteotomy more objectively.

Materials and Methods:

Radiographs of 101 feet were studied to derive mean values for dimensions of the hallux proximal phalanx in the general population. Based on these we calculated the size of osteotomy required for given corrections.

Results:

The mean hallux width 5 mm distal to the apex of the articular surface differed between males and females. In males the mean width was 18 mm (95% CI 17.5 to 18.8) and in females 15 mm (95% CI 14.5 to 15.5). For a 10 degree correction, an osteotomy with a 3 mm base would be required.

Conclusion:

Although the Akin osteotomy dimensions are commonly estimated, a more objective method of planning the osteotomy is presented. The method can also be applied to any closing wedge osteotomy.

Clinical Relevance:

We believe this method of the Akin osteotomy can improve the accuracy of the surgery.
A Biomechanical Analysis of a Tensioned Suture Device in the Fixation of the Ligamentous Lisfranc Injury
Authors: Pelt Christopher E. , Bachus Kent N. , Vance Richard E. , Beals Timothy C.
Published: July 2011

Background:

We hypothesized that using a cadaveric Lisfranc ligamentous injury model, abduction stress would provoke greater post-injury motion than axial weightbearing between the medial cuneiform (MC1) and the base of the second metatarsal (MT2). Second, we hypothesized that both a tensioned suture-button device and a rigid screw fixation method could maintain a reduction and similarly restrain motion to intact (pre-injury) levels.

Materials and Methods:

Motion was measured between MC1 and MT2 in five matched pairs of human cadaveric feet. Specimens were tested prior to injury, following a transverse ligamentous Lisfranc injury, and then randomized to either screw or tensioned suture-button fixation. Axial then abduction loads were applied. Measurements were repeated after one thousand loading cycles.

Results:

With both axial and abduction loads, statistically significant differences in motion were detected between the intact and post-injury conditions, although the magnitudes were greater with abduction (6.8 mm versus 2.0 mm, p = 0.000004). With abduction loads, both fixation methods were effective in restraining motion to pre-injury levels (screw fixation: 1.5 mm intact versus 1.1 mm post-fixation, p = 0.487; suture-button fixation: 1.3 mm intact versus 2.1 mm post-fixation, p = 0.063), and similarly, both devices restrained motion to less than post-injury levels (screw fixation: 8.1 mm post-injury versus 1.1 mm post-fixation, p = 0.001; suture-button fixation: mean 5.5 mm post-injury versus 2.1 mm post-fixation, p = 0.0002). No significant differences in these patterns were detected following cyclic loading.

Conclusion:

Small, though statistically significant, amounts of motion are produced between MC1 and MT2 with axial loading after a ligamentous Lisfranc injury. With abduction stress, we were able to show a significantly greater difference between pre- and post-injury motion and the ability of both fixation methods to restrain motion to pre-injury levels.

Clinical Relevance:

Abduction stress may be valuable when diagnosing and testing the transverse ligamentous Lisfranc injury. Both suture-button and screw fixation methods restrain motion at the Lisfranc complex.
Biomechanical Evaluation of a Locking and Nonlocking Reconstruction Plate in an Osteoporotic Calcaneal Fracture Model
Authors: Blake Matthew H. , Owen John R. , Sanford Timothy S. , Wayne Jennifer S. , Adelaar Robert S.
Published: July 2011

Background:

This study evaluated the effects of locking vs nonlocking configuration on the biomechanical performance of a calcaneal reconstruction plate in an osteoporotic cadaveric model.

Materials and Methods:

A Saunders II B type calcaneal fracture was created in ten matched pair of cadaveric calcanei. Each pair was fixed with the Ascension calcaneal reconstruction plate using either locking or nonlocking screws in the same hole pattern. Specimens were axially loaded for 1000 cycles through the talus followed by load to failure. Statistical comparisons were made between the locking and nonlocking constructs on the displacements during cyclic loading as well as construct stiffness and load achieved at selected fragment displacements.

Results:

No significant difference was detected between the locking and nonlocking constructs in displacement during cyclic loading ( p >0.2) for the numbers available. Similarly no significant difference was found in stiffness of the constructs between the groups: 445.7 ± 148.8 (N/mm ± SD) for the locking plate and 395.2 ± 127.7 for the nonlocking plate ( p >0.14). The load achieved at 2 mm displacement of the posterior fragment for the two groups were not different: locking plate at 744.6 ± 237.2 N and nonlocking plate at 739.3± 269.7 N ( p >0.99).

Conclusion:

This study did not reveal a mechanical advantage to locking technology for calcaneal fractures with the selected plate and fracture model.

Clinical Relevance:

While locking plate technology has shown mechanical advantages for fracture management in other osteoporotic models, in our fracture model and plating construct, this was not found. It is still unclear which fixation technique is most beneficial in these calcaneal fractures.
Technical Tip: The Crescentic Shelf: A Modified Ludoff Osteotomy
Authors: Ross Steven D. K.
Published: July 2011

Level of Evidence: V, Expert Opinion
STAR™ Ankle: Long-Term Results
Authors: Mann Jeffrey A. , Mann Roger A. , Horton Eric
Published: July 2011

Background:

There has been a resurgence of interest in total ankle replacement (TAR) due to improved results with newer prostheses. However, long-term survivorship data has been limited. The STAR™ Ankle prosthesis is the first three-part prosthesis approved for use in the United States.

Materials and Methods:

Eighty-four total ankle replacements were performed in 80 patients using the STAR™ Ankle prosthesis and followed prospectively. Postoperatively, patients were evaluated with the AOFAS score for pain and function, and serial radiographs were evaluated for stability and alignment of the prosthesis. Implant failure, secondary procedures, and complications were recorded.

Results:

Ninety-one percent of prostheses remain implanted at an average followup of 9.1 years. The probability of implant survival was 96% at 5 years and 90% at 10 years. An average 39-point improvement in the AOFAS ankle-hindfoot score was noted, from a mean of 43 to a mean of 82 points. We noted a statistically significant increase in both average pain and function sub-scores. Postoperative range of motion averaged 4.5 degrees of dorsiflexion and 35 degrees of plantarflexion. Ninety-two percent of the patients were satisfied with their outcome. Ten patients (13%) developed concerning osteolytic lesions. Change in prosthetic alignment and adjacent joint arthritis were similar to previous reports. We report 21 complications, which included 14 additional surgical procedures.

Conclusion:

The first U.S. prospective long-term survivorship data with the STAR™ Ankle prosthesis found it to be an excellent long-term option for the treatment of ankle arthritis. Level of Evidence: IV, Case Series
Transient Bone Marrow Edema of the Foot and Ankle and its Association with Reduced Systemic Bone Mineral Density
Authors: Sprinchorn Anna E. , O'Sullivan Richard , Beischer Andrew D.
Published: July 2011

Background:

Transient bone marrow edema in the foot and ankle is an uncommon condition that should be distinguished from early avascular necrosis, stress fracture, or bone bruise. The diagnosis is based on the clinical presentation of pain with weightbearing without a history of trauma, combined with typical findings on magnetic resonance imaging. The etiology is not known, but recent case reports have suggested a possible link to systemic osteoporosis. This study examined the relationship between transient bone marrow edema of the foot and ankle and low systemic bone mineral density.

Material and Methods:

Over a period of 2 years, ten patients (eight women and two men) who were referred to our foot and ankle clinic were diagnosed as having transient bone marrow edema. Their mean age was 59 years. All underwent dual energy X-ray absorptiometry (DEXA) scan and were tested for serum vitamin D levels. The patients were treated with either a controlled ankle motion (CAM) walker or a stiff-soled postoperative shoe and all recovered in 5 to 10 months.

Results:

Four patients were found to have osteoporosis and five had osteopenia. Only one patient had normal bone density. Serum vitamin D levels were low in nine patients, and normal in one.

Conclusion:

Our study found a strong association with transient bone marrow edema in the foot and ankle and low systemic bone mineral density, which appears to be due to a vitamin D deficiency. We recommend that, when TBME is diagnosed, patients should be referred for assessment and treatment of their bone mineral density. Level of Evidence: IV, Retrospective Case Series
First Metatarsal Length Change after Basilar Closing Wedge Osteotomy for Hallux Valgus
Authors: Day Thomas , Charlton Timothy P. , Thordarson David B.
Published: July 2011

Background:

Hallux valgus deformities with large intermetatar-sal angles require a more proximal metatarsal procedure to adequately correct the deformity. Due to the relative ease of a closing wedge osteotomy, this technique was adopted but with concern over first metatarsal shortening. In this study, we primarily evaluated angular correction and first metatarsal shortening.

Materials and Methods:

We evaluated 70 feet in 57 patients (average age, 54 years) with 52 female and five male. The average followup was 14 (range, 6 to 45) months. The charts were reviewed for the presence of metatarsalgia. Digital radiographic measurements were made for pre- and postoperative hallux valgus and intermetatarsal angles, dorsiflexion angle of the first metatarsal, and absolute and relative shortening of the first metatarsal.

Results:

The average hallux valgus angle improved from 31 to 11 degrees ( p < 00001) and intermetatarsal angle from 13.2 to 4.4 angles ( p < 00001). The absolute shortening of the first metatarsal was 2.2 mm and relative shortening was 0.6 mm. There was 1.3 degrees of dorsiflexion on average.

Conclusion:

Excellent correction of the deformity with minimal dorsiflexion or new complaints of metatarsalgia was found with this technique. The new method of assessing the relative shortening found to be less than the absolute shortening, which we feel more accurately reflects the functional length of the first metatarsal. Level of Evidence: IV, Retrospective Case Series
Extremely Proximal Fractures of the Fifth Metatarsal in the Developmental Age
Authors: Riccardi Giovanni , Riccardi Domenico , Marcarelli Marco , Regno Nicola Del , Riccio Vincenzo
Published: July 2011

Background:

Numerous studies document the high incidence of this type of fracture of the foot in childhood due to the presence of the growth plate of the apophysis of the fifth metatarsal. Our aim in this study was to evaluate the presence and morphology of the growth nucleus and correlate its presence with fractures of the apophysis of the fifth metatarsal.

Materials and Methods:

Between 2001 and 2003, we reviewed the radiographs of 481 patients (558 feet) between 6 months and 16 years that were diagnosed with a fracture. We evaluated for the presence and morphology of the growth nucleus of the base of the fifth metatarsal in the 7- to 16-year age group because this is the time interval in which the nucleus becomes visible radiographically.

Results:

We identified the nucleus of the base of the fifth metatarsal in 115 patients for a total of 132 feet. A fracture of the fifth metatarsal was found in 12.8%. A misdiagnosis had been made in 47%. Misdiagnosis was strictly related to the presence of the growth nucleus of the apophysis except two cases where an accessory bone was present.

Conclusions:

Our study demonstrated a much higher incidence of the presence of the growth nucleus than documented in previous reports and that its morphology varied widely in relation to the stage of maturity of the patient and the radiographic technique. Its presence led to a high rate of misdiagnosis of a fracture. Level of Evidence: IV, Retrospective Case Series
Relationship of the Scarf Valgus-Inducing Osteotomy of the Calcaneus to the Medial Neurovascular Structures
Authors: Vermeulen Katrien , Neven Enrico , Vandeputte Geoffroy , Van Glabbeek Francis , Somville Johan
Published: July 2011

Background:

The Scarf valgus inducing osteotomy of the calcaneus is an operative technique to correct varus deformity of the hindfoot. It is versatile with significant corrective power; however, the neurovascular structures are in close proximity on the medial side and thus may be harmed during the osteotomy. Moreover, because this type of osteotomy can cause a great lateral translation, traction of the medial neurovascular structures is possible. We performed an anatomic study to evaluate the medial soft tissues after a lateralizing Scarf-type calcaneal osteotomy.

Materials and Methods:

The osteotomies were carried out on ten fresh-frozen cadaver specimens. We performed the osteotomy and induced valgus. Then we performed a medial dissection to identify the important medial structures: the medial and lateral plantar nerve (MPN, LPN) and the posterior tibial artery (PTA). We noted their relation to the osteotomy and their integrity.

Results:

In several cases, one or more of the structures were sectioned. In five cases, all the structures crossed the osteotomy, four of which even a transection of one or both of the plantar nerves occurred. Although the PTA crossed the osteotomy in eight specimens, there was no transection of this structure.

Conclusion:

Scarf osteotomy of the calcaneus is a highly corrective osteotomy. However, caution must be exercised when performing as the medial neurovascular structures cross the osteotomy lines and transection can occur.

Clinical Relevance:

When performing the osteotomy one should keep in mind that vigorous sawing and large displacement can cause damage to the medial neurovascular structures.
Deep Peroneal Nerve Injury following External Fixation of the Ankle: Case Report and Anatomic Study
Authors: Lui T. H. , Chan Lap Ki
Published: July 2011

Background:

We present a case of deep peroneal nerve injury after application of external fixator and conducted a cadaveric study of the relationship of the deep peroneal nerve to the lateral tibial cortex.

Materials and Methods:

A case of toe drop after application of the external fixator is reported. Twelve cadaveric lower legs were dissected to identify the course of the deep peroneal nerve. The tibia were divided into four Zones with equal length. The course of the nerve through each Zone of the tibia was studied Result: In Zone 1, the deep peroneal nerve went around the fibular neck and was found on the interosseous membrane at the distal portion of Zone 1. In Zone 2, the nerve still lay on the interosseous membrane in all specimens at the posterior edge of the lateral tibia. In Zone 3, the nerve moved away from the interosseous membrane and had direct contact with the tibia in nine specimens. In Zone 4, the nerve was on the anterior surface of the distal tibia.

Conclusion:

The deep peroneal nerve can be injured during the application of a unilateral frame ankle external fixator. The nerve is particularly at risk in Zone 2 and 3.

Clinical Relevance:

The study provided an anatomic basis for the safe application of a unilateral external fixator of the tibia. Level of Evidence: V, Expert Opinion
Tendon Transfer for Anterior and Posterior Tibialis Dysfunction following Hip Dislocation: Case Report
Authors: Hepper Clifford T. , Johnson Jeffrey E.
Published: July 2011

Level of Evidence: V, Expert Opinion
Halving the Knots in Percutaneous Tendo Achilles Repair: Technique Tip
Authors: Phillips Alistair , Schranz Peter
Published: July 2011

Level of Evidence: V, Expert Opinion
Efficacy of Paracetamol versus Diclofenac for Grade II Ankle Sprains
Authors: Lyrtzis Christos , Natsis Konstantinos , Papadopoulos Christos , Noussios Georgios , Papathanasiou Efthymia
Published: July 2011

Background:

Ankle sprains are usually treated with the RICE protocol often with nonsteroidal anti-inflammatory drugs (NSAID) for pain reduction. We evaluated the effect of diclofenac, an NSAID, versus paracematol in the reduction of pain and acute edema of severe ankle sprains.

Materials and Methods:

Ninety patients, 18 to 60 years old, with Grade II acute ankle sprains were randomized into two groups. Group A (45 patients) received for the first 10 days diclofenac 75 mg orally twice per day. Group B (45 patients) received paracetamol 500 mg orally three times per day for the same period. We evaluated ankle joint edema with the Figure-of-Eight method and with the volumetric method, as well as pain with the Visual Analogue Scale (VAS) in both groups.

Results:

The patients had no significant differences concerning their baseline values ( p > 0.05). The ankle joint edema was decreased in both groups ( p < 0.001) but there was more edema in group A than in group B at the third post-traumatic day with both measurement methods (p = 0.028/0.025). By the tenth post-traumatic day no difference was found. Pain decreased in both groups at the third day and at the tenth day ( p < 0.001).

Conclusion:

According to these results, diclofenac and paracetamol had the same effect on pain reduction of ankle sprains but more acute ankle edema was present in patients who were treated with diclofenac than in patients who were treated with paracetamol. Level of Evidence: I, Prospective, Randomized Study
Ankle Tourniquet Pain Control in Forefoot Surgery: A Randomized Study
Authors: Burg Alon , Tytiun Yehezkel , Velkes Steven , Heller Snir , Haviv Barak , Dudkiewicz Israel
Published: July 2011

Background:

Forefoot surgery is often performed under regional anesthesia in awake patients, using tourniquet or Esmarch bandage to obtain a bloodless field. The purpose of this study was to examine the value and need for local tourniquet pain control using local subcutaneous analgesic mixture in patients undergoing forefoot surgery under ankle block anesthesia.

Materials and Methods:

We prospectively randomized 56 patients who underwent forefoot surgery under ankle block to receive either subcutaneous local anesthetic mixture under the tourniquet or no additional anesthetic. We checked for local tourniquet pain score (VAS 0 to 100) and skin condition during and after the procedure.

Results:

The tourniquet was quite tolerable in both groups, with an average VAS score of 7 to 21. No difference was observed between groups throughout most of the procedure. No correlation between VAS scores and procedure length or patient's age or gender was found.

Conclusion:

An ankle tourniquet was well-tolerated by patients without need for local anesthetic beneath the cuff. Level of Evidence: II, Prospective Comparative Study
Closed Intramedullary Screw Fixation for Nonunion of Fifth Metatarsal Jones Fracture
Authors: Habbu Rohan A. , Marsh Robert S. , Anderson John G. , Bohay Donald R.
Published: July 2011

Background:

Nonunion following a proximal fifth metatarsal metaphyseal-diaphyseal or Jones fracture can cause considerable pain with high morbidity and loss of work. Treatment should aim for early union, thus allowing early return to activity. The present study evaluated the outcomes and the time required for union following closed intramedullary screw fixation for this condition.

Materials and Methods:

Between January 2005 to August 2009, 14 patients were diagnosed with nonunion following a Jones fracture. Mean age at surgery was 49 years. Mean duration from injury to surgery was 28 weeks. All nonunions were fixed with a single intramedullary screw inserted from the base of the fifth metatarsal without opening the nonunion site. Serial postoperative radiographs were evaluated to determine union. Time required for return to activity was determined. Outcome was assessed with help of pain scores. Mean followup was 27 months.

Results:

Union was achieved in all 14 patients with one delayed union. Mean time to union was 13.3 (range, 8 to 20) weeks. All patients were able to start unassisted full weightbearing without pain at mean 10.2 weeks. Overall pain score improved from a preoperative mean of 5.4 to postoperative mean of 1.0. Complications included one deep infection, one delayed wound healing and one sural neuroma.

Conclusion:

Closed intramedullary screw fixation achieved an excellent union rate when used in the treatment of nonunion of a Jones fractures. Level of Evidence: IV, Retrospective Case Series
Limitations of Standard Fluoroscopy in Detecting Rotational Malreduction of the Syndesmosis in an Ankle Fracture Model
Authors: Marmor Meir , Hansen Erik , Han Hyun Kyu , Buckley Jenni , Matityahu Amir
Published: July 2011

Background:

When treating ankle fractures with associated syndesmosis injury, failure to anatomically reduce the syndesmosis may lead to poor outcome. While shortening and posterior subluxation of the distal fibula are readily detected by intraoperative fluoroscopy, it is unclear how well malrotation can be assessed. The ability of fluoroscopy to detect rotational malre-duction of the fibula was the subject of this study.

Materials and Methods:

Distal fibula fractures with complete syndesmotic injury were produced in ten cadaveric ankles. Two Kirschner wires were used to fix the fibula in neutral (0 degrees), 10 to 30 degrees of external rotation (ER), and 10 degrees to 30 degrees of internal rotation (IR). Using C-arm fluoroscopy tibio-fibular clear space and tibio-fibular overlap in the AP and mortise views, and posterior fibular subluxation in the lateral view were measured to assess reduction of the syndesmosis.

Results:

The radiographic indices were able to detect as little as 10 degrees of IR but were within their normal range in up to 30 degrees of ER. When assessing for a 2mm difference compared to the intact ankle, sensitivity of all indices were low after more than 15 degrees ER, but high and clinically useful after more than 15 degrees of IR.

Conclusion:

Radiographic indices for syndesmosis disruption could not detect ER malreduction of the syndesmosis of up to 30 degrees.

Clinical Relevance:

In the setting of ankle fractures with syndesmosis disruption, fixing the fibula in as much as 30 degrees of external rotation may go undetected using intraoperative fluoroscopy alone.
Anterolateral and Medial Locking Plate Stiffness in Distal Tibial Fracture Model
Authors: Yenna Zachary C. , Bhadra Arup K. , Ojike Nwakile I. , ShahulHameed AbdulSalam , Burden Robert L. , Voor Michael J. , Roberts Craig S.
Published: July 2011

Background:

The purpose of this study was to compare the axial and torsional stiffness between anterolateral and medial distal tibial locking plates in a pilon fracture model.

Materials and Methods:

The biomechanical stiffness of anterolateral or medial plated pilon fracture models was evaluated. Six Sawbones Composite Tibiae with a simulated pilon fracture representing varus or valgus comminution (OTA 43-A2.2) were plated with a Synthes 3.5-mm contoured LCP anterolateral or medial locking distal tibia plate. Load as a function of axial displacement and torque as a function of angular displacement were recorded. Each tibia was tested with a fracture wedge in place and removed with a medial and then anterolateral plate.

Results:

Loading the tibial plateau medial to the central axis, no significant difference in mean stiffness between the anteroateral and medial plates was demonstrated with the fracture wedge in place. A significant difference was demonstrated with the wedge removed. Loading the plateau posterior to the central axis, no significant difference in mean stiffness between plates was demonstrated with the wedge in place or removed. With the wedge in place, there was a significant difference in mean torsional stiffness for clockwise rotation, but not counterclockwise rotation. With the wedge removed, no significant difference appeared in mean stiffness for clockwise and counterclockwise rotation.

Conclusion:

Distal tibia extra-articular fractures stabilized with anterolateral or medial locking plate constructs demonstrated no statistically significant difference in biomechanical stiffness in compression and torsion testing.

Clinical Relevance:

We believe this study indicates the primary concern when treating a pilon fracture may be soft-tissue considerations. Further clinical studies are required before definitive changes can be recommended regarding pilon fracture fixation.
Bicortical Structural Autograft Harvest during Medializing Calcaneal Osteotomy: Technique Tip
Authors: Desai Sarang
Published: July 2011

Level of Evidence: V, Expert Opinion
Endoscopic Debridement of the Achilles Insertion, Bursa, and the Calcaneal Tubercle with an Accessory Posterolateral Portal: Technique Tip
Authors: Carmont Michael R. , Fawdington Ross A. , Mei-Dan Omer
Published: July 2011

Level of Evidence: V, Expert Opinion
Calcaneal Traction Pin Placement Simplified: A Cadaveric Study
Authors: Kwon John Y. , Ellington J. Kent , Marsland Daniel , Gupta Sanjeev
Published: July 2011

Background:

The tibial neurovascular bundle and sural nerve are at risk with errant pin placement during transcalcaneal pin placement. The purpose of this study was to determine a relative safe zone using a single osseous landmark to establish a technique applicable in the presence of trauma. We describe the neural anatomy anatomically and radiographically, giving surgeons a reliable and relatively safe technique for transcalcaneal pin placement.

Materials and Methods:

Twenty-four cadavers were dissected for the major medial neurovascular structures and the sural nerve. The closest distance from the neurovascular structures to the posterior inferior calcaneus was measured.

Results:

The mean distance from the posterior inferior calcaneus to the closest major medial neurovascular structure was 3.4 cm (SD ± 0.36; range, 2.6 to 4.1 cm). The mean distance to the sural nerve was 3.4 cm (SD ± 0.54; range, 2.3 to 4.6 cm). According to the 95% confidence intervals, a relative safe zone of 3.1 cm as a radius from the posterior inferior calcaneus was determined.

Conclusion:

A relatively safe zone of 3.1 cm based on 95% confidence intervals as described as a radius from the posterior inferior calcaneus can be used for transcalcaneal pin placement in most cases without injury to the medial neurovascular bundle or sural nerve. However anatomic variation may result in the neurovascular bundle being within this zone.

Clinical Relevance:

We describe a surgical technique for reliable placement of a transcalcaneal pin within this relative safe zone and a safe distance from the closest neurovascular structure. Level of Evidence: V, Expert Opinion
Conservation of Houbara Bustards using Interspecific Chimeras
Authors: Wernery Ulrich , Liu Chunhai , Baskar Vijay , Guerineche Zhor , Khazanehdari Kamal A. , Saleem Shazia , Kinne Jörg , Wernery Renate , Griffin Darren K. , Chang Il-Kuk
Published: July 2011

Embryonic gonadal tissue was dissected individually from Houbara bustard embryos at eight days post-incubation. Houbara bustard gonadal cells containing gonadal primordial germ cells (gPGCs) were injected into the blood stream of White Leghorn chicken (Gallus gallus domesticus) embryos, producing 83/138 surviving male chimeric embryos, of which 35 chimeric roosters reached sexual maturity after 5 months. The incorporation and differentiation of Houbara bustard PGCs in chimeric chicken testis were assessed by PCR with Houbara bustard species-specific primers and 31.3% (5/16) gonads collected from the injected chicken embryos showed the presence of donor Houbara bustard cells. A total of 302 semen samples from 34 chimeric roosters were analyzed and eight were confirmed as germ line chimeras. Semen samples from these eight roosters were used to artificially inseminate three female Houbara bustards. Subsequently, 45 Houbara bustard eggs were obtained and incubated, two of which were fertile. One egg hatched as a male live born Houbara bustard and the other was female but died before hatching.
Potential for Somatic Nuclear Transfer Technology in Domestic Chickens
Authors: Tajima Atsushi
Published: July 2011

The development of mammalian somatic nuclear transfer techniques by Wilmut et al. in 1997 provided a new option for conserving animal genetic resources; however, this technique cannot be applied directly to avian species due to the anatomical and physiological differences between avian and mammalian embryos. A basic strategy for producing nuclear transferred avian offspring with somatic nuclear transferred primordial germ cells (snt-PGCs) was described in 2002. Under this scenario, somatic nuclear offspring could be produced through germline chimeras by transferring snt-PGCs into the bloodstream of early chicken embryos. In the present study, a series of experiments have been carried out to produce somatic nuclear transferred chickens.
Falcon Breeding in the Middle East and Facility Design Considerations
Authors: Le Mesurier David
Published: July 2011

The captive breeding of falcons in the Middle East has been carried out since the mid 1970s. In this paper, we will look at the timeline for the development of breeding centres in the Middle East and design considerations used for one project built in the desert heat of Dubai.
Factors Causing Sex differences in Birds
Authors: Arnold Arthur P. , Itoh Yuichiro
Published: July 2011

In recent years, increasing evidence suggests that sex differences in the phenotype of all tissues are influenced by the inequality of effects of sex chromosome genes in the two sexes. In birds, genes on the Z chromosome are not well dosage compensated, so that most Z genes are expressed higher in ZZ male cells than in ZW female cells. The sex difference in expression of Z and W genes is likely to cause sex differences within cells, in addition to the sex differences caused by different levels of testicular and ovarian hormones. The sexual imbalance in cell physiology has implications for aviculture and novel developments in the poultry industry.
Interspecific Duck–Chicken Chimeras
Authors: Gao Junshuang , Sha Jin , Yuan Fang , Zhang Wenxin , Rui Lei , Tang Xiaoyan , Han Haitang , Shao Yujing , Liu Haiwen , Yan Li , Li Zandong
Published: July 2011

The production of quail–Peking duck, Peking duck–quail and Maya duck–chicken chimeras by transferring donor (quail, Peking duck and Maya duck) blastoderm cells into the subgerminal cavity of the recipient (Peking duck, quail and chicken) eggs is described. Production of chimeras by transferring blastoderm cells into the recipient embryo should provide a basis for the investigation of fertilisation barriers in interspecies germline chimeras. It might help to protect endangered birds, contribute to further understanding of physiology and embryonic development in poultry, and provide a technical method for poultry transgenics.
Improving Rates of Germline Transmission in Chimeric Chickens Using Busulfan Solubilised Sustained-Release Emulsion
Authors: Tagami Takahiro , Nakamura Yoshiaki
Published: July 2011

The administration of a busulfan solubilised sustained-release emulsion was used to improve the efficiency of endogenous primordial germ cell (PGC) depletion in early chicken embryos. Busulfan was solubilised in N,N-dimethylformamide and diluted 10-fold in phosphate-buffered saline [PBS(–)]. The sustained-release emulsion was prepared by mixing equal amounts of busulfan solubilised solution and sesame oil using a filter. The appropriate time and dose of busulfan sustained-release emulsion administration were established to optimise our novel germline replacement technique. Injecting busulfan sustained-release emulsion into the yolk of recipient embryos at zero hours of incubation did not disturb the movement and proliferation of donor cells during the generation of germline chimeras. A dose of 100 μg of busulfan resulted in the greatest reduction of endogenous PGCs in embryonic gonads and the most successful hatchability of sterilised embryos. Test-cross analysis revealed that the germline transmission rate in busulfan treated chickens was significantly higher than in non-treated controls (99.5 versus 6.0%). This unique and efficient germline transmission system has potential applications in the conservation of endangered and/or rare avian species.
Variations in Nest-Site Parameters in Breeding Waterbirds at Lake Zarivar, Western Iran
Authors: Barati Ahmad , Ataei Farhad , Esfandabad Bahman Shams , Shabanian Naghi , Etezadifar Farzaneh
Published: July 2011

Variations in nest-site parameters were studied at Lake Zarivar, Kurdistan Province, Western Iran in 2007 and 2008. This study was applied for six breeding waterbird species: Great-crested Grebe (Podiceps cristatus), Little Grebe (Tachybaptus ruficollis), Moorhen (Gallinula chloropus), Coot (Fulica atra), Water Rail (Rallus aquaticus) and Whiskered Tern (Chlidonias hybrida). A total of 205 nest-sites were studied in terms of five environmental factors: vegetation density and height, water depth, distance to open water, as well as distance to the nearest nest of the conspecific species were measured. Great-crested Grebes selected areas of deeper waters, possibly to increase feeding efficiency. All species were directly dependent on water for nesting, except for the Water Rail, which established its nest in muddy areas with higher vegetation density and height. Nests were at a higher density for the Whiskered Terns than in other species. Overall, mean water depth at nesting sites was lower in the 2008 breeding season and total breeding population of waterbirds decreased. Evaluating and monitoring of habitat quality of breeding species urges conservation measures with regard to transformations occurring at this freshwater lake ecosystem.
Low-frequency bursts of horizontally polarized waves in the Arctic sea-ice cover
Authors: Marsan David , Weiss Jérôme , Métaxian Jean-Philippe , Grangeon Jacques , Roux Pierre-François , Haapala Jari
Published: July 2011

We report the detection of bursts of low-frequency waves, typicallyf= 0.025 Hz, on horizontal channels of broadband seismometers deployed on the Arctic sea-ice cover during the DAMOCLES (Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies) experiment in spring 2007. These bursts have amplitudes well above the ambient ice swell and a lower frequency content. Their typical duration is of the order of minutes. They occur at irregular times, with periods of relative quietness alternating with periods of strong activity. A significant correlation between the rate of burst occurrences and the ice-cover deformation at the ∼400 km scale centered on the seismic network suggests that these bursts are caused by remote, episodic deformation involving shearing across regional-scale leads. This observation opens the possibility of complementing satellite measurements of ice-cover deformation, by providing a much more precise temporal sampling, hence a better characterization of the processes involved during these deformation events.
Spatial patterns of surface hoar properties and incoming radiation on an inclined forest opening
Authors: Lutz Eric R. , Birkeland Karl W.
Published: July 2011

Avalanche hazard evaluation relies in part on representative snowpack stability observations. Thus, understanding the spatial patterns of snowpack instabilities and their environmental determinants is crucial. This case study integrates intensive field observations with spatial modeling to identify associations between incoming radiation, surface hoar development and its subsequent shear strength across an inclined forest opening. We examined a buried surface hoar layer in southwest Montana, USA, over five sampling days, collecting 824 SnowMicroPen resistance profiles and performing 352 shear frame tests. Spatial models of incoming long- and shortwave radiation were generated for the surface hoar formation period using modeled hemispheric sky visibility, physically based parameters and the Bird Clear Sky Radiation Model in a Geographic Information System. Before burial, the surface hoar persisted despite moderate winds and relatively high air temperatures. The buried surface hoar layer thickness varied between 3 and 21 mm within a distance of 30 m. Modeled incoming radiation explained spatial variations in layer thickness and shear strength. In areas exposed to large amounts of radiation, the surface hoar layer was strong and thin, while areas with limited incoming radiation (due to high sky visibility and shading) possessed a thicker surface hoar layer that sheared more easily. This demonstrates the usefulness of microclimate modeling for slope-scale avalanche hazard evaluation. We also identify that over the 3 week sample period, strengthening occurred without thinning of the surface hoar layer.
Modelling distributed and channelized subglacial drainage: the spacing of channels
Authors: Hewitt Ian J.
Published: July 2011

Models are proposed for channelized and distributed flow of meltwater at the base of an ice sheet. The volumes of both channel and distributed systems evolve according to a competition between processes that open drainage space (e.g. sliding over bedrock, melting of the ice) and processes that close it (e.g. viscous creep of the ice due to a positive effective pressure). Channels are generally predicted to have lower water pressure and therefore capture water from the surrounding regions of distributed flow. There is a natural length scale associated with the distributed system that determines the width of the bed from which water can be drawn into a channel. It is suggested that this determines the spacing between major channels and that this may be reflected in the spacing of eskers. A more permeable distributed system results in more widely spaced, and therefore larger, channels. Calculations of the flow into the head of a channel reveal that there is a critical discharge necessary for it to form, and provide a criterion for where channels can exist.
Effects of flow regime and sensor geometry on snow avalanche impact-pressure measurements
Authors: Baroudi D. , Sovilla B. , Thibert E.
Published: July 2011

Impact pressures of snow avalanches have been measured at the Swiss Vallée de la Sionne experimental test site using two kinds of sensor placed at different locations in the avalanche flow. Pressures measured in a fast dry-snow avalanche and a slow wet-snow avalanche are compared and discussed. The pressures recorded using the two types of sensor in the dense flow of a dry-snow avalanche agree well, showing negligible dependence on the measurement device. On the other hand, significantly different pressures are measured in the slow dense flow of a wet-snow avalanche. This is attributed to the slow drag and bulk flow of this type of avalanche, leading to the formation and collapse of force-chain structures against the different surfaces of the sensors. At a macroscopic scale, limit state analysis can be used to explain such a mechanism by a shear failure occurring between freely flowing snow and a confined snow volume against the sensor, according to a Mohr–Coulomb failure criterion. The proposed model explains (1) how impact pressure can be up to eight times higher than hydrostatic snow pressure in wet cohesive slow avalanches and (2) its dependence on sensor geometry.