Biomedical subjects

Peter Kloen

Publications and source records attributed to Peter Kloen.

At least 19 recordsLinked to original sources

PubMed2006

Minimally invasive treatment of pilon fractures with a low profile plate: preliminary results in 17 cases.

OBJECTIVE: To determine the results of "biologic fixation" with a minimally invasive plating technique using a newly designed low profile "Scallop" plate in the treatment of pilon fractures. DESIGN: Retrospective case series. SETTING: A tertiary referral center. PATIENTS/PARTICIPANTS: Seventeen patients were treated between 1999 and 2001 for a tibial plafond fracture at the Hospital for Special Surgery with a newly designed low-profile plate. Eleven of the fractures (65%) were high-energy injuries. Two fractures were open. INTERVENTION: Staged surgical treatment with open reduction and fixation of the fibular fracture and application of an external fixator was performed in 12 cases. As soon as the soft tissues and swelling allowed, i.e. skin wrinkling, the articular surface was reconstructed and simply reduced, if necessary through an small incision, and the articular block was fixed to the diaphysis using a medially placed, percutaneously introduced flat scallop plate. In the remaining five cases the operation was performed in one session. MAIN OUTCOME MEASUREMENTS: Time to healing and complications including delayed union, non-union, instrument failure, loss of fixation, infection, quality of reduction and number of reoperations were evaluated. Quality of results and outcome were graded using the ankle-hindfoot-scale and a modified rating system. RESULTS: All patients went on to bony union at an average time of 14 weeks. There were no plate failures or loss of fixation/reduction. Two superficial wound-healing problems resolved with local wound care. At an average follow up of 17 months (range 6-29 months) eight patients (47%) had an excellent result; seven (41%) had a fair result whereas two (12%) had a poor result. The average ankle-hindfoot-score was 86.1 (range 61-100). Four patients have had the hardware removed and one of them is awaiting an ankle arthrodesis. CONCLUSIONS: Based on these initial results, it appears that a minimally invasive surgical technique including new low profile plate can decrease soft tissue problems while leading to fracture healing and obtaining results comparable with other more recent series. We believe that this new "Scallop Plate" is effective for the treatment of pilon fractures and should be used in conjunction with a staged procedure in the acute trauma setting.

Adult↗

PubMed2006

Treatment of subtrochanteric nonunions.

The purpose of this retrospective study was to evaluate our results of treating subtrochanteric nonunions with a (AO/ASIF) blade plate. We treated a total of 32 patients (33 hips) with a subtrochanteric nonunion with a blade plate. Outcome measures were time to healing, complications after the index-operation and the Merle d'Aubigne hip score at follow-up. Union was achieved in 32 of the 33 hips after an average of 5 months. Complications were seen in nine patients (nine hips); five complications required re-intervention and four minor complications were treated conservatively. According to the Merle d'Aubigne hip score, 10 patients were rated as excellent, 15 as good and 7 as fair. This study shows that treatment of a subtrochanteric nonunion with a blade plate consistently leads to bony union with a good to excellent hip score in the vast majority of the patients (25 out of 33 hips).

Adolescent↗

PubMed2006

Anterior tension band plating for anterior tibial stress fractures in high-performance female athletes: a report of 4 cases.

Stress fracture of the anterior tibial cortex is an extremely challenging fracture to treat, especially in the high-performance female athlete who requires rapid return to competition. Previous reports have not addressed treating these fractures in the world-class athlete with anterior plating. We hypothesize that anterior plating is a biomechanically sound approach to treatment of these fractures, and will lead to an earlier return to full activity than either nonoperative treatment or intramedullary nailing. We present a retrospective series of 4 case reports of 4 world-class female athletes with stress fractures of the anterior tibial cortex treated by anterior plating between 2001 and 2004. Average follow-up was 15 months (range 12 to 48 mo). Anterior tension band plating resulted in fracture healing in all 4 cases and return to full activity at a mean of 10 weeks. All patients returned to preinjury competitive levels. There were no complications of infection, nonunion, or malunion. Anterior tension-band plating of an anterior tibial stress fracture leads to rapid fracture healing and return to competition for high-performance female athletes. This approach should be considered in those athletes who wish to avoid the more prolonged convalescence associated with nonoperative treatment, or the problems, especially of the knee, associated with intramedullary nailing.

Adult↗

PubMed2006

Two and three-dimensional computed tomography for the classification and management of distal humeral fractures. Evaluation of reliability and diagnostic accuracy.

BACKGROUND: Complex fractures of the distal part of the humerus can be difficult to characterize on plain radiographs and two-dimensional computed tomography scans. We tested the hypothesis that three-dimensional reconstructions of computed tomography scans improve the reliability and accuracy of fracture characterization, classification, and treatment decisions. METHODS: Five independent observers evaluated thirty consecutive intra-articular fractures of the distal part of the humerus for the presence of five fracture characteristics: a fracture line in the coronal plane; articular comminution; metaphyseal comminution; the presence of separate, entirely articular fragments; and impaction of the articular surface. Fractures were also classified according to the AO/ASIF Comprehensive Classification of Fractures and the classification system of Mehne and Matta. Two rounds of evaluation were performed and then compared. Initially, a combination of plain radiographs and two-dimensional computed tomography scans (2D) were evaluated, and then, two weeks later, a combination of radiographs, two-dimensional computed tomography scans, and three-dimensional reconstructions of computed tomography scans (3D) were assessed. RESULTS: Three-dimensional computed tomography improved both the intraobserver and the interobserver reliability of the AO classification system and the Mehne and Matta classification system. Three-dimensional computed tomography reconstructions also improved the intraobserver agreement for all fracture characteristics, from moderate (average kappa [kappa2D] = 0.554) to substantial agreement (kappa3D = 0.793). The addition of three-dimensional images had limited influence on the interobserver reliability and diagnostic characteristics (sensitivity, specificity, and accuracy) for the recognition of specific fracture characteristics. Three-dimensional computed tomography images improved intraobserver agreement (kappa2D = 0.62 compared with kappa3D = 0.75) but not interobserver agreement (kappa2D = 0.24 compared with kappa3D = 0.28) for treatment decisions. CONCLUSIONS: Three-dimensional reconstructions improve the reliability, but not the accuracy, of fracture classification and characterization. The influence of three-dimensional computed tomography was much more notable for intraobserver comparisons than for interobserver comparisons, suggesting that different observers see different things in the scans-most likely a reflection of the training, knowledge, and experience of the observer with regard to these relatively uncommon and complex injuries.

Adult↗

PubMed2006

Orthopaedic trauma in the pregnant patient.

Trauma affects up to 8% of pregnancies and is the leading cause of death among pregnant women in the United States. A pregnancy test is mandated for all females of childbearing age who are involved in trauma. Orthopaedic trauma in the pregnant patient is managed similarly to that for all trauma patients. Initial resuscitation efforts should focus on the pregnant patient because stable patient vital signs provide the best chance for fetal survival. In the stable patient, fetal assessment and a pelvic examination are mandatory. Radiographs as well as abdominal ultrasound of the patient and fetal ultrasound are useful. No known biologic risks are associated with magnetic resonance imaging, and no specific fetal abnormalities have been linked with standard low-intensity magnetic resonance imaging. Emergency surgery can be safely performed in most pregnant patients. Avoiding patient hypotension and using left lateral decubitus positioning increase the likelihood of success for the patient and fetus. An experienced multidisciplinary team consisting of an obstetrician, perinatologist, orthopaedic surgeon, anesthesiologist, radiologist, and nursing staff will optimize the treatment of both the pregnant patient and her fetus.

Female↗

PubMed2005

Operative treatment of acetabular fracture during pregnancy: a case report.

We present a case of operative treatment of an acetabular fracture in a pregnant patient in her third trimester. The natural fear of causing harm to the pregnancy or fetus is understandable in such situations, but should not lead to withholding appropriate care. Successful treatment of these rare cases is possible with careful pre-, peri-, and postoperative evaluation of the mother and fetus by a multidisciplinary team.

Accidents, Traffic↗

PubMed2005

Delayed bladder rupture after symphyseal hardware failure.

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Bone Plates↗

PubMed2004

Loss of alignment after surgical treatment of posterior Monteggia fractures: salvage with dorsal contoured plating.

PURPOSE: To review the results of internal fixation with a dorsal contoured plate in patients with malalignment after internal fixation of a posterior Monteggia fracture. METHODS: Seventeen patients with malalignment after surgical treatment of a posterior Monteggia fracture were treated with realignment of the ulna and fixation with a contoured dorsal plate. Fifteen patients had loose fixation and 12 patients had subluxation or dislocation of the ulnohumeral joint. Sixteen patients had fracture of the radial head and 9 patients had fracture of the coronoid process. Nine patients had ancillary procedures on the radial head, 4 had ancillary procedures on the coronoid, 5 had hinged external fixation, and one had fascial arthroplasty. Seven patients had another surgery before the final evaluation related to a complication in 6 patients and a to subsequent injury in 1 patient. RESULTS: At the final evaluation at an average of 59 months the fracture was healed and the ulnohumeral joint was reduced concentrically in all 17 patients. The average arc of elbow flexion was 108 degrees and the average arc of forearm rotation was 134 degrees. The average American Shoulder and Elbow Surgeons Elbow Evaluation Score was 88. According to the system of Broberg and Morrey, the final result was rated excellent for 5 patients, good for 9, fair for 2, and poor for 1. One patient had fascial arthroplasty as part of the index procedure and 9 patients had radiographic signs of ulnohumeral arthrosis. CONCLUSIONS: Malalignment after surgical treatment of posterior Monteggia fractures often is associated with unstable fixation. Dorsal contoured plating of the ulna in combination with other procedures can help salvage a malaligned posterior Monteggia fracture with satisfactory function restored in the majority of patients.

Adult↗

PubMed2004

Nonunions of the distal tibia treated by reamed intramedullary nailing.

OBJECTIVE: The purpose of this study is to determine the efficacy of reamed intramedullary nailing in the treatment of nonunions of the distal one-fourth of the tibia. Nonunions of the distal tibia are particularly difficult to treat given the short distal segment, the proximity to the ankle joint, and the fragile soft-tissue envelope. Intramedullary nailing is an attractive solution to this problem because it avoids extensive dissection, and the implant remains intraosseous, posing minimal problem for the soft tissues. DESIGN: Retrospective review of patient charts and radiographs. SETTING: Tertiary care orthopaedic hospital. PATIENTS/PARTICIPANTS: Thirty-two patients with nonunions of the distal one-fourth of the tibia. Prior treatments included casting, internal fixation with plates and screws, intramedullary nailing, and external fixation. Seven patients had a history of infection, but no patient had signs of active infection at the time of surgery. INTERVENTION: Study patients were treated by reamed, locked intra-medullary nailing. MAIN OUTCOME MEASUREMENTS: Main outcome measurements included time to union, correction of deformity, and complications including infection and reoperation. RESULTS: Average length of follow-up was 25 months (range 4-81 months). Twenty-nine out of 32 patients achieved union at an average of 3.5 months after reamed, locked intramedullary nailing. Of the remaining three, 2 patients united after dynamization (one at 4 months after dynamization and the other at 7 months), and the third patient united 4 months after exchange nailing. Deformity was corrected to a maximum of 4 degrees in all planes. Four patients had positive intraoperative cultures, and only 2 required removal of the nail after achieving union to control infection. There were no signs of chronic osteomyelitis in these 2 patients at the date of the last follow-up visit; 5.5 years and 2 years following nail removal. CONCLUSIONS: Reamed, locked intramedullary nailing is a reliable and safe procedure in the treatment of nonunions in the distal one-fourth of the tibia, even in the setting of prior infection or external fixation. It allows for excellent correction of deformity, which is an essential component of the procedure.

Adolescent↗

PubMed2004

Locking compression plates for osteoporotic nonunions of the diaphyseal humerus.

Poor bone quality increases the technical difficulty and complications of operative treatment of nonunions and delayed unions of the diaphyseal humerus in older patients. Plates with screws that lock to the plate (transforming each screw into a fixed blade) are intended to improve the fixation of poor quality bone. Twenty-four patients (20 women, four men) with an average age of 72 years (range, 52-86 years) were followed up for a minimum of 12 months after locking compression plate fixation of an osteopenic delayed union (nine patients) or nonunion (15 patients) of the diaphyseal humerus. Twelve patients had iliac crest cancellous bone grafts, two patients had local graft, and 13 patients had demineralized bone applied to the fracture site. All the fractures eventually healed; two healed after a second procedure for autogenous bone grafting in patients who initially received demineralized bone. Using a modification of the Constant and Murley shoulder score, the results were good or excellent in 22 patients, and fair in two patients. Locking compression plates provide stable fixation of poor quality bone in patients with delayed union or nonunion of the humerus. Successful union and restoration of function are achieved in most patients. We no longer consider osteoporosis a contraindication to operative fixation of an ununited fracture of the humeral diaphysis.

Aged↗

PubMed2004

ORIF of delayed unions and nonunions of distal humeral fractures. Surgical technique.

BACKGROUND: The purpose of the present retrospective study was to evaluate the results of open reduction and internal fixation of delayed unions and nonunions of fractures of the distal part of the humerus. METHODS: Between 1976 and 2001, fifty-two patients with a delayed union (thirteen patients) or nonunion (thirty-nine patients) of the distal part of the humerus were treated with open reduction and internal fixation along with selective elbow joint arthrolysis and bone-grafting. The average time to presentation was eighteen months (range, two to 192 months) after the injury. Thirty-nine of the fifty-two patients had undergone an average of 1.6 previous operations. There were twenty-seven supracondylar, six transcondylar, thirteen intercondylar, two lateral condylar, and four medial condylar delayed unions or nonunions. The average duration of follow-up was thirty-three months (range, three to 198 months). RESULTS: Fifty-one of the fifty-two patients had healing of the delayed union or nonunion after the index operation; the average time to union was six months (range, two to twenty-four months). The average range of elbow motion increased from 71 degrees preoperatively to 94 degrees postoperatively. Complications included two superficial infections, two deep infections, and five cases of ulnar neuropathy. Fifteen patients (29%) needed additional surgery after the index procedure. Specifically, seven patients underwent removal of prominent hardware; six underwent hardware removal along with excision of heterotopic bone, ulnar neurolysis, and/or manipulation under anesthesia; one underwent irrigation and débridement; and one underwent compartment release. CONCLUSIONS: Open reduction through an extensile exposure and rigid internal fixation consistently results in healing of a delayed union or nonunion of the distal part of the humerus. An improved range of motion of the elbow can be achieved by securing the site of the nonunion and performing aggressive elbow joint arthrolysis and soft-tissue releases in patients with severe contractures.

Fracture Fixation, Internal↗

PubMed2004

Complex open trauma of the shoulder: a case report.

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Follow-Up Studies↗

PubMed2004

Bilateral clavicle non-unions treated with anteroinferior locking compression plating (LCP): a case report.

The author reports the case of a 30-year-old female patient with bilateral atrophic non-union of the clavicle; the latter both healed after internal fixation with a locking compression plate fixed on the anteroinferior aspect of the clavicle, combined with autologous cancellous bone grafting. The advantages of the anteroinferior positioning of the plate on the clavicle are presented.

Adult↗

PubMed2003

Subtrochanteric fracture after cannulated screw fixation of femoral neck fractures: a report of four cases.

Subtrochanteric fractures after screw or pin fixation of femoral neck fractures are a recognized complication. No literature is available on this complication after fixation using the recently popularized cannulated screws. We present our experience in treating four of these complications. The common denominator for all four patients seemed to be an entry point in the lateral cortex below the level of the most inferior edge of the lesser trochanter.

Aged↗

PubMed2003

Open reduction and internal fixation of delayed unions and nonunions of fractures of the distal part of the humerus.

Adolescent↗

PubMed2003

Bilateral Monteggia fractures.

The current concepts of anatomic and stable fixation followed by early mobilization in Monteggia fractures have clearly resulted in improvements in treatment and outcome. Bilateral Monteggia fractures are unusual and to the best of our knowledge have not been the subject of any reports in the literature. In this case report, we describe the operative technique for treating bilateral Monteggia fractures and the common pitfalls associated with this treatment. Despite the surgical and rehabilitative challenges posed by our patient's case, excellent results were obtained for both elbows.

Accidental Falls↗

PubMed2002

MRI assessment of the posterior acetabular wall fracture in traumatic dislocation of the hip in children.

Traumatic hip dislocations associated with posterior wall fractures of the acetabulum in the pediatric population are in general a consequence of high-energy trauma. After expeditious reduction, instability mandates for further diagnosis and intervention. Plain radiographs or computerized tomography (CT) scans can misjudge the involvement of the posterior wall of the acetabulum due to the partially calcified nature of the pediatric bone. We present two cases of pediatric traumatic hip dislocation associated with posterior wall fractures of the acetabulum. In both cases, obvious postreduction instability was noted without conclusive findings of etiology on plain X-rays or CT scans. Magnetic resonance imaging (MRI) disclosed an extensive posterior wall traumatic involvement in both cases and helped to decide in favor of open reduction of the hip and internal fixation of the posterior wall fragment.

Acetabulum↗

PubMed2002

Open reduction and internal fixation of humeral nonunions : a biomechanical and clinical study.

BACKGROUND: Several studies have compared different methods for fixation of the midpart of the humeral shaft, but there are only scattered data regarding which type of plate construct provides the best fixation for humeral nonunion. The objectives of this study were (1) to obtain objective data on the performance of four different plate constructs used for fixation of humeral nonunion, and (2) to report our clinical experience with plate fixation of thirty-seven nonunions of the midpart of the humeral shaft. METHODS: In the first part of the study, four plate constructs were compared in a Sawbones model. The groups consisted of (1) a posterior limited-contact dynamic compression plate alone; (2) a posterior limited-contact dynamic compression plate and an interfragmentary screw; (3) a posterior limited-contact dynamic compression plate, a lateral 3.5-mm reconstruction plate, and an interfragmentary screw; and (4) a posterior limited-contact dynamic compression plate and a lateral 3.5-mm reconstruction plate. Tests were performed with use of an MTS Bionix machine in anterior-posterior four-point bending, medial-lateral four-point bending, and external rotation torque. In the second part of the study, the charts of thirty-seven consecutive patients in whom a nonunion of the midpart of the humeral shaft had been treated with plate fixation were reviewed retrospectively. The average age of the patients was forty-eight years (range, thirteen to seventy-eight years). Nineteen patients were treated with a single posterior plate, and eighteen were treated with a two-plate construct with the plates parallel and lying at 90 degrees to each other. All of the nonunions were treated with bone-grafting, and an interfragmentary screw was used in thirty-six of the thirty-seven patients. Radiographs and the clinical status were evaluated at an average of thirteen months postoperatively. RESULTS: The biomechanical testing showed that the two-plate constructs were significantly stiffer than the single-plate constructs in all test modes (p < 0.05). In the clinical part of the study, thirty-four (92%) of the nonunions healed without complications at an average of 4.8 months. Two nonunions treated with the two-plate construct and one treated with one plate failed to heal. CONCLUSIONS: No significant difference in the healing rate was found between the two clinical groups (p = 0.4, beta = 0.9), and the overall healing rate was 92%. However, a two-plate construct with the plates at right angles is mechanically stiffer than a single-plate construct, which might be helpful if rigid stabilization of the humerus at the midshaft level is needed.

Adolescent↗