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Biomedical subjects

Michael J Gardner

Publications and source records attributed to Michael J Gardner.

35 records · Page 2Linked to original sources
PubMed2005

Complete exposure of the articular surface for fixation of patellar fractures.

Anterior tension band fixation constructs are among the mainstay of treatment of patella fractures and lead to reliable results with simple transverse fracture patterns. However, comminuted fractures of the patella require much more extensive articular reconstruction than interdigitating two large fragments to achieve a good result. In this report, we describe a technique for exposure, reduction, and stabilization of patella fractures that allows for direct visual reduction of the articular surface. Subsequent devices are applied directly to the bony surfaces of the patella without soft-tissue interposition, which distinguishes it from traditional approaches. This technique may be used to ensure articular surface congruity in simple transverse fractures and may be particularly useful in comminuted fractures when patellar excision would otherwise be considered.

Adult↗
PubMed2005

Low incidence of ulnar nerve injury with crossed pin placement for pediatric supracondylar humerus fractures using a mini-open technique.

OBJECTIVES: Several recent studies have suggested that medial pinning in pediatric supracondylar humerus fractures leads to increased rates of ulnar nerve injury. The purpose of this study was to determine the risk of iatrogenic ulnar nerve injury in a consecutive series of supracondylar fractures treated using a standardized technique of crossed pin placement. DESIGN: Single cohort retrospective. SETTING: Metropolitan university tertiary care center. PATIENTS AND PARTICIPANTS: Seventy-one consecutive children with Gartland type II or type III supracondylar humerus were treated surgically by 2 pediatric orthopaedic surgeons at 1 institution between 1995 and 2000 using a medial mini-open and cross-pinning technique. Sixty-five patients were available for follow-up (92%). INTERVENTION: Patients were treated with a combination of medial and lateral pins using a mini-incision technique. MAIN OUTCOME MEASUREMENTS: Outcomes analyzed included ulnar nerve injury and clinical and radiographic evidence of healing. RESULTS: The study group consisted of 65 patients, of whom 29 (45%) presented with Gartland type III fractures, and the remaining 36 (55%) presented with a type II fracture. There were no ulnar nerve motor injuries. One patient was noted to have transient sensory changes in the ulnar nerve distribution postoperatively, which resolved by the 1-week follow-up visit. All patients were noted to have normal ulnar motor and sensory nerve function at final follow-up (average 4.5 months). No cases of nonunion, malunion, or infection were identified during the follow-up period. CONCLUSIONS: The rate of iatrogenic ulnar nerve injury with this specific technique of crossed pin placement for extension-type supracondylar humerus fractures was extremely low in this series. A single case of transient ulnar sensory neuropraxia occurred. Our series demonstrates that crossed pin fixation can be performed safely and reliably and is an appropriate treatment option for unstable supracondylar humerus fractures.

Bone Nails↗
PubMed2005

The extended anterolateral acromial approach allows minimally invasive access to the proximal humerus.

Lateral approaches to the proximal humerus have been limited by the position of the axillary nerve. Extensive surgical dissection through a deltopectoral approach may further damage the remaining tenuous blood supply in comminuted fractures. The purpose of our study was to explore a direct anterolateral, less invasive approach to the proximal humerus. Twenty cadaver shoulders were dissected using the extended anterolateral acromial approach through the anterior deltoid raphe. Multiple parameters were measured regarding the axillary nerve. The nerve was easily palpable in all specimens as it exited the quadrilateral space, and predictably was found and protected deep to the raphe, approximately 35 mm from the prominence of the greater tuberosity. Examination of the entire anterior nerve revealed that no branches besides the main motor trunk crossed the deltoid raphe. Subsequently, this approach was used in 16 patients with proximal humerus fractures, none of whom has had complications related to the surgical approach. This minimally invasive surgical approach seems to be safe, and may be useful in treating proximal humerus fractures.

Acromion↗
PubMed2005

Not all spondylolisthesis grading instruments are reliable.

Spondylolisthesis is the slippage of one vertebral body on an adjacent level, and occurs commonly at the lumbosacral junction in children. Many radiographic measurement instruments have been described to predict progression and need for intervention. We evaluated the reliability of eight common grading instruments. Four raters reviewed 30 lateral radiographs of the lumbar spine in patients with spondylolisthesis. Each rater measured each film twice, and had mean individual correlation coefficients of at least 0.76 (range, 0.76-0.91). Only three measurements had interobserver correlations greater than 0.75 (slip percentage, Meyerding's grade, and sacral inclination), which corresponded to excellent reliability. For intraobserver reliability, six measurements had correlations greater than 0.75 (all except kyphosis angle and lumbar index), indicating excellent agreement. Slip percent, Meyerding's grade, and sacral inclination had excellent interobserver agreement and intraobserver agreement.

Adolescent↗
PubMed2005

Radiographic measurements do not predict syndesmotic injury in ankle fractures: an MRI study.

UNLABELLED: Several radiographic measurements have been described and are used to determine ligamentous injury in ankle fractures, particularly of the deltoid and syndesmosis complex. Because the accuracy of these radiographic measurements has been questioned, we sought to evaluate their accuracy using magnetic resonance imaging as an indicator for injury. Seventy patients with closed ankle fractures were entered prospectively into the study, and all had standard plain radiographic evaluations before reduction (anteroposterior, lateral, and mortise) and magnetic resonance imaging. Four radiographic measurements were made on initial ankle injury films: tibiofibular clear space on the anteroposterior view, tibiofibular overlap on the anteroposterior and mortise views, and medial clear space on the mortise view. These radiographic measurements and their association with magnetic resonance imaging findings then were analyzed. A medial clear space measurement greater than 4 mm correlated with disruption of the deltoid and the tibiofibular ligaments. We found no association between the tibiofibular clear space and overlap measurements on radiographs with syndesmotic injury on magnetic resonance imaging scans. LEVEL OF EVIDENCE: Prognostic study, Level II-1 (retrospective study). See the Guidelines for Authors for a complete description of levels of evidence.

Ankle Injuries↗
PubMed2005

Periprosthetic patellar fracture after an open knee dislocation.

We present a patient who sustained an open knee dislocation with a periprosthetic fracture of the patella and who was treated satisfactorily with tension band wiring and a conservative rehabilitation program. In addition to describing this unique combination of injuries, we review the literature on the treatment of periprosthetic patellar fractures. Although internal fixation of these fractures historically has provided unpredictable results, we think that it is warranted if the patella has adequate bone stock.

Bone Wires↗
PubMed2005

The mechanical behavior of locking compression plates compared with dynamic compression plates in a cadaver radius model.

OBJECTIVE: The purpose of this cadaveric study was to compare the mechanical behavior of a locked compression plate, which uses threaded screw heads to create a fixed angle construct, with a dynamic compression plate construct in a cadaver radius model. DESIGN: Mechanical study with cyclic testing and high-speed optical motion analysis. SETTING: Biomechanics laboratory at an academic institution. PATIENTS/PARTICIPANTS: Eighteen pairs of fresh-frozen human cadaver radii were divided into 3 groups of 6 to be tested as a group in each of the following force applications: anteroposterior (AP) bending, mediolateral bending, or torsion. INTERVENTION: Each bone was osteotomized leaving a 5-mm fracture gap and then fixed with a plate. For each pair, 1 radius received a standard plate (limited-contact dynamic compression plates; LC-DCP), the contralateral radius was fixed with a locking compression plate (LCP), and specimens underwent cyclic loading. Normalized stiffness, average energy absorbed, and Newton-cycles to failure were calculated. In addition, a 3-dimensional, high-speed, infrared motion analysis system was used to evaluate motion at the fracture site. MAIN OUTCOME MEASUREMENTS: Construct stiffness, fracture site motion, cycles to failure, and energy absorption. Repeated measures ANOVA were used to detect differences between groups with time. RESULTS: In the torsion group, LCP specimens failed at 60% greater Newton-cycles than the LC-DCP (1473 vs. 918; P < 0.05). In the AP group, the LC-DCP absorbed significantly greater energy during 10,000 cycles compared with the LCP group (P < 0.05). The 2 constructs demonstrated different biomechanical behavior with time. As cycling progressed in the LC-DCP specimens under torsion testing, stiffness (measured at the actuator at the bone ends) did not change significantly; however, fracture motion (measured at the fracture surfaces) decreased significantly (P = 0.04). The LCP specimens did not display similar behavior. CONCLUSIONS: Our findings indicated that LCP constructs may demonstrate subtle mechanical superiority compared with the LC-DCP. The LCP specimens had less energy absorption in the AP group and survived longer in the torsion group. Discordance of motion between measurement regions was observed only in the LC-DCP torsion group, and may have been caused by plate-bone slippage or bone-screw subcatastrophic failure. However, many other compared parameters were found to be similar, and the clinical significance of the few differences found between constructs mandates further investigation.

Biomechanical Phenomena↗
PubMed2005

Interventions to improve osteoporosis treatment following hip fracture. A prospective, randomized trial.

BACKGROUND: Treatment of osteoporosis following a hip fracture has been notoriously poor. Many efforts have been made to improve treatment rates. The purpose of this study was to determine whether a perioperative inpatient intervention program, involving patient education and providing a list of questions for the primary care physician, increased the percentage of patients in whom osteoporosis was addressed following a hip fracture. METHODS: A prospective, randomized trial involving eighty patients who had been admitted to an academic medical center with a low-energy hip fracture was conducted. During their hospitalization, the study group patients were engaged in a fifteen-minute discussion regarding the association between osteoporosis and hip fractures, the efficacy of dual-energy x-ray absorptiometry scans in the diagnosis of osteoporosis and of bisphosphonates in its treatment, and the importance of medical follow-up for osteoporosis management. These patients were also provided with five questions regarding osteoporosis treatment to be given to their primary medical physician, and they were reminded about the questions during a follow-up telephone call six weeks later. The patients in the control group received a brochure describing methods for preventing falls. Both groups were contacted by telephone at six months after discharge to determine whether osteoporosis had been addressed. Positive indicators of intervention included assessment of bone mineral density with dual-energy x-ray absorptiometry and initiation of antiresorptive therapy. RESULTS: The average age in each group was eighty-two years, and 78% of the patients were female. Four patients in each group did not survive through the six-month follow-up period and were excluded from the trial. Fifteen (42%) of the thirty-six patients who had been randomized to the study group, compared with only seven (19%) of the thirty-six patients in the control group, had their osteoporosis addressed by their primary physician. This difference between the groups was significant (p = 0.036). CONCLUSIONS: Patients who were provided with information and questions for their primary care physician about osteoporosis were more likely to receive appropriate therapeutic intervention than were patients who had not received the information and questions. Orthopaedic surgeons have a unique opportunity to improve the rate of osteoporosis treatment in the perioperative period following a hip fracture by educating patients and directing them toward channels for long-term osteoporosis management.

Accidental Falls↗
PubMed2004

Surgical treatment of pediatric femoral shaft fractures.

PURPOSE OF REVIEW: Femoral shaft fractures are among the most common fractures in children. Depending on the patient's age, fracture location, pattern, mechanism of injury, and associated injuries, several different treatment options exist. The purpose of this review is to discuss these different clinical situations and the recommended treatment methods, as well as to characterize the latest literature and recommendations. RECENT FINDINGS: In the past several years, there have been significant changes in the approach to the treatment of pediatric femoral shaft fractures, particularly in school-aged children. Young children have traditionally been treated conservatively with good results, and this method is still currently advocated. Adolescents over the age of 12 are generally treated with rigid intramedullary rods. However, in children between the ages of 5 and 12, new surgical treatment modalities have been tested with good outcomes, and, as new data emerge, these methods are becoming preferable to conservative treatment. SUMMARY: Children who sustain femoral shaft fractures can present difficult challenges to both orthopedists and pediatricians. A recent shift in treatment in children between ages of 5 and 12 from nonoperative to surgical intervention has led to shorter hospital stays and earlier return to activity with reliable fracture healing.

Adolescent↗
PubMed2004

Osteoporotic femoral neck fractures: management and current controversies.

Osteoporosis is a pervasive disease among the growing elderly population. Femoral neck fractures are often a direct result of osteoporosis and are challenging to treat. Surgical interventions seek to return the patient to preinjury function as quickly as possible, but many obstacles exist. Disruption of the blood supply occurs regardless of the fracture pattern, and in the active elderly population, reduction and fixation should be done as soon as possible to minimize healing problems. Closed reduction with percutaneous cannulated screw instrumentation is currently the fixation method of choice, but even with meticulous technique, moderate complication rates persist. Newer devices and biologic bone augmentation cement show promise in decreasing postoperative fracture collapse. Patients in whom a stable reduction cannot be achieved or who have a limited life expectancy should undergo arthroplasty. Unipolar and bipolar arthroplasty have both been effective in restoring function and have been the standard of care in these patients. Recent evidence suggests that active elderly patients who have acetabular disease or severely displaced fractures may benefit most from primary total hip arthroplasty.

Aged↗
PubMed2004

Has locked plating completely replaced conventional plating?

The 2 main approaches to fracture plate fixation--compression plating and internal splinting--result in differing biomechanics and subsequent healing response patterns. A number of advantages to using the newer internal fixators have been described, but there are still several indications for traditional compression plating.

Biomechanical Phenomena↗
PubMed2004

A minimally invasive approach for plate fixation of the proximal humerus.

Plate fixation for unstable fractures of the proximal humerus has seen mixed results as evidenced by the trials of new methods of fixation. The deltopectoral surgical approach is most frequently used and requires significant muscle retraction and soft tissue stripping to expose the lateral humeral neck. This may contribute to avascular necrosis and fixation failure. Lateral approaches have been limited to 5 cm distal to the acromion because of the course of the anterior branch of the axillary nerve. A recent anatomic study has demonstrated the predictability of the position of the axillary nerve as it crosses the anterior deltoid raphe, which allows it to be isolated and protected, and dissection can be extended distally. In addition, no accessory motor branches to the anterior head of the deltoid cross the raphe, so extending an incision through the raphe after protecting the main motor branch of the axillary does not place the innervation to the anterior deltoid at risk. This surgical approach allows exposure of the proximal humerus and indirect reduction of the fracture, with subsequent locking plate fixation, adhering to the principles of biological fixation.

Bone Nails↗
PubMed2003

The aging spine: new technologies and therapeutics for the osteoporotic spine.

Osteoporosis results in low-energy fractures of the spine. The load necessary to cause a vertebral fracture is determined by the characteristics related to the vertebral body structure, mineral content, and quality of bone. Radiographic techniques centered on dual X-ray absorptiometry (DXA) permit a determination of bone mass and fracture risk. Current medical therapies principally using bisphosphonate and pulsatile PTH profoundly decrease the risk of fracture (50+%). Fall prevention strategies can further decrease the possibility of fracture. A comprehensive approach to osteoporosis can favorably alter the disease.

Absorptiometry, Photon↗
PubMed2002

Improvement in the undertreatment of osteoporosis following hip fracture.

BACKGROUND: Osteoporosis is a common disease characterized by decreased bone mass and increased fracture risk in postmenopausal women and the elderly. Hip fractures are among the most common consequences of osteoporosis and unfortunately usually occur late in the course of the disease. When a patient is admitted to the hospital with a fragility hip fracture, a unique opportunity for diagnosis and treatment presents itself. Fortunately, several medications have proven to be effective in lowering the risk of future fractures. The purposes of the present study were to test the hypothesis that most fragility hip fractures go untreated and to determine whether educational efforts to raise physician awareness have led to an improvement in osteoporosis treatment rates. METHODS: A retrospective cohort study was performed with use of the patient databases at two university medical centers and one university-affiliated community hospital. The charts of 300 randomly selected patients were sorted with use of ICD-9 (International Classification of Diseases, Ninth Revision) codes for femoral neck fractures. There were 100 patients from each center, with twenty-five patients from each year between 1997 and 2000. The admitting diagnosis, mechanism of injury, admission medications, procedures performed during hospitalization, and discharge medications were then extracted and analyzed. During this period, the National Osteoporosis Foundation established guiding principles for the treatment of fragility fractures. RESULTS: Of the seventy-five patients from all centers for each year from 1997 to 2000, 11%, 13%, 24%, and 29%, respectively, were discharged with a prescription for some medication targeting osteopenia, either supplemental calcium or an antiosteoporotic medication (estrogen, calcitonin, a bisphosphonate, or raloxifene). A trended chi-square analysis of this increase revealed a p value of <0.001, indicating that this improvement in treatment was unlikely due to chance alone. Fifty-eight (19.3%) of the 300 patients in the study received a prescription at the time of discharge. However, forty of these patients (13.3% of the overall group) received calcium and only eighteen (6.0% of the overall group) received a medication to actively prevent bone resorption and treat osteoporosis. In addition, no patient underwent a bone density scan while in the hospital. CONCLUSIONS: Elderly patients and postmenopausal women who are admitted to the hospital and diagnosed with a low-energy femoral neck fracture have been undertreated for osteoporosis. However, over the four years of the present study, there was a significant increase in the rate of treatment. It is hoped that treatment rates will continue to increase in the future with continued educational efforts.

Aged↗
PubMed2002

Orthopedic issues after cerebrovascular accident.

Patients who have had a cerebrovascular accident with resultant hemiplegia often present to the orthopedic surgeon with characteristic complaints and deformities. The most common of these include muscle spasticity and contracture, shoulder pain, hip fracture, and heterotopic ossification. Although some of these disorders are clinically evident, others may be easily overlooked. The purpose of this article is to summarize the most common orthopedic aspects of hemiplegic patients who have had a cerebrovascular accident.

Activities of Daily Living↗
PubMedDate not supplied

Surgical dislocation of the hip for fractures of the femoral head.

Traumatic dislocations of the hip are high-energy injuries that frequently occur with fractures of the femoral head. Controversy exists regarding many aspects of the treatment of these fractures, but following reduction, large displaced head fragments require open reduction and internal fixation. Traditionally, an anterior approach to the hip joint has been used for surgical access to the femoral head, but this incision often results in limited visualization and subsequent difficulty with anatomic reduction. Recently, a surgical hip dislocation technique has been described for acetabular fractures and deformities of the proximal femur. At our institution, this technique has been used for femoral head fractures resulting in superior visualization and fracture stabilization. This article details the technique and its application.

Adolescent↗