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Douglas E Padgett

Publications and source records attributed to Douglas E Padgett.

10 recordsLinked to original sources
PubMed2006

Integrity of repaired posterior structures after THA.

Various studies have questioned the benefit of repairing the posterior structures after total hip arthroplasty because their integrity can appear disrupted at followup. However, these studies did not directly examine the posterior structures. We hypothesized that repaired posterior structures remain intact after total hip arthroplasty, and that their integrity could be evaluated by ultrasonography. We performed evaluations in the hips of 18 patients that had either the short external rotators and capsule repaired, or the capsule, short external rotators, and quadratus femoris repaired. Nine patients in each group were examined using ultrasonography at 6 weeks and 3 months postoperatively. The short external rotators and capsule were intact in 89% of patients in both groups at 6 weeks and 3 months postoperatively. At both time points, the quadratus femoris had continuity in 44% of hips with the standard posterior repair and 78% of hips with the enhanced posterior repair (p = 0.15). Ultrasonography can be used to effectively assess the integrity of the posterior repair after total hip arthroplasty. The posterior structures were intact in the majority of patients 3 months after total hip arthroplasty.

Adult↗
PubMed2006

Influence of total hip design on dislocation: a computer model and clinical analysis.

Dislocation following hip arthroplasty remains problematic. While the etiology of dislocation may be multifactorial, implant system design may play a role. Using a computer aided design program, virtual range of motion of several commonly implanted designs was performed with prosthetic interference representing impingement used as an endpoint. Implants with small diameter head size (22 mm) and a larger trunion geometry (type II taper) demonstrated impingement in flexion at less than 90 degrees , suggesting an increased risk for dislocation. To investigate this clinically, we performed a review of a consecutive series of 254 primary hip arthroplasties performed by a single surgeon using an implant with a type II taper (Biomet, Warsaw, IN). At a minimum 2 year followup, 12 patients with 12 hips (4.8%) had at least one episode of dislocation. Stratified by head size, the dislocation rates were 3.6% for 28 mm, 4.8% for 26 mm, and 18.8% for 22 mm bearings. These findings support the notion that computer aided design modeling of implant systems is useful in evaluating range of motion and this technique could be employed during the design of any new implant system.

Arthroplasty, Replacement, Hip↗
PubMed2005

Impingement of acetabular cups in a hip simulator: comparison of highly cross-linked and conventional polyethylene.

We hypothesized that the reduction in toughness that accompanies elevated levels of cross-linking in ultrahigh-molecular weight polyethylene would lead to increased wear and damage in acetabular cups under conditions of impingement with the neck of the femoral component. Test cups were exposed to 2.8, 10, and 20 Mrad of gamma irradiation and were tested in a simulator, incorporating impingement during every wear cycle. Wear behavior was compared based on wear rate, observations of damage, and the number and morphology of wear particles. The 10-Mrad cups had the lowest rate (15.2 +/- 5.1 mg/Mc), followed by the 2.8-Mrad (40.1 +/- 4.2 mg/Mc) and 20-Mrad (67.9 +/- 24.2 mg/Mc) groups. The wear damage was most severe in the 20-Mrad cups, although all 3 groups showed pitting and delaminating. Wear rates and damage of highly cross-linked polyethylene cups were significantly higher in an impingement wear test than in previous simulator studies.

Acetabulum↗
PubMed2005

Magnetic resonance imaging of the hip: detection of labral and chondral abnormalities using noncontrast imaging.

PURPOSE: Traditional imaging techniques have limited ability to detect subtle chondral and labral injuries of the hip. We performed a retrospective review of patients who underwent magnetic resonance imaging (MRI) of the hip and subsequent hip arthroscopy in order to evaluate the ability of optimized, noncontrast MRI to identify tears of the acetabular labrum and defects in articular cartilage. TYPE OF STUDY: Retrospective review of a consecutive sample. METHODS: Between January 1997 and July 2000, 92 patients had MRI of the hip, followed by arthroscopic surgery of that hip by 1 of 2 surgeons (R.B., D.E.P.). Two musculoskeletal MR radiologists blinded to the initial MRI and surgical findings, independently interpreted the studies, looking for the location and degree of articular cartilage and acetabular labral pathology. RESULTS: Of the 92 patients studied, each of 2 radiologists correctly identified 83 (94%) and 84 (95%) of the 88 labral tears present at surgery, respectively. There was 92% interobserver agreement on the MRI studies. For articular cartilage defects on the femoral head and acetabulum, there was good agreement (92% and 86% within 1 grade) between MRI and surgical grading and between the 2 MR readers (kappa of 0.8 for femoral head cartilage and 0.7 for acetabular cartilage). CONCLUSIONS: This study shows that noncontrast MRI of the hip, using an optimized protocol, can noninvasively identify labral and chondral pathology. Such information may facilitate deciding which patients warrant surgical intervention, thus preserving hip arthroscopy as a therapeutic tool. LEVEL OF EVIDENCE: Level II, Development of Diagnostic Criteria Study.

Acetabulum↗
PubMed2005

Preoperative planning for primary total hip arthroplasty.

Preoperative planning is of paramount importance in obtaining reproducible results in modern hip arthroplasty. Planning helps the surgeon visualize the operation after careful review of the clinical and radiographic findings. A standardized radiograph with a known magnification should be used for templating. The cup template should be placed relative to the ilioischial line, the teardrop, and the superolateral acetabular margin, so that the removal of the supportive subchondral bone is minimal and the center of rotation of the hip is restored. When acetabular abnormalities are encountered, additional measures are necessary to optimize cup coverage and minimize the risk of malposition. Templating the femoral side for cemented and cementless implants should aim to optimize limb length and femoral offset, thereby improving the biomechanics of the hip joint. Meticulous preoperative planning allows the surgeon to perform the procedure expediently and precisely, anticipate potential intraoperative complications, and achieve reproducible results.

Arthroplasty, Replacement, Hip↗
PubMed2004

The unstable total hip replacement.

Instability after total hip arthroplasty (THA) is not a rare occurrence. Numerous factors have been associated with dislocation including surgical approach, implant design, failure to restore proper hip mechanics and soft tissue restraints, and patient variables such as early postoperative compliance, soft tissue integrity, and neurologic conditions such as poor proprioception. A thorough understanding of the mechanism of dislocation, timing, and direction of dislocation is mandatory in formulating an approach toward treatment. The radiographic evaluation should evaluate hip mechanics including component orientation, adequacy of leg lengths, and restoration of offset in the frontal and sagittal planes. The treatment of the unstable total hip replacement is based on numerous variables including the timing of instability, direction, and mechanism. Instability in the early postoperative period in the hip with proper orientation and restored mechanics often is treated successfully with patient reeducation and use of adjunctive bracing. The treatment of the recurrent dislocator can be more difficult. Although reestablishing proper mechanics and orientation can be successful in many instances, some patients continue to have dislocation. Constrained acetabular liners have significantly improved the success rate of reducing the incidence of dislocation, but problems related to premature wear and dislodgement are a major concern. The use of larger articulating bearing surfaces used with the newer cross-linked polyethylene may provide the solution to instability minimizing the concerns related to constrained components.

Arthroplasty, Replacement, Hip↗
PubMed2003

The efficacy of 500 CentiGray radiation in the prevention of heterotopic ossification after total hip arthroplasty: a prospective, randomized, pilot study.

A prospective, randomized, pilot study comparing 500 cGy (group A) versus 1,000 cGy (group B) radiation treatment for the prevention of heterotopic bone in a consecutive group of high-risk patients undergoing total hip arthroplasty was performed. Treatment was initiated within ninety-six hours and given in equal, divided doses: 2 doses for group A and 5 doses for group B. No statistically significant difference was found in the demographics between the 2 groups. At follow-up evaluation, the distribution of heterotopic bone according to the Brooker classification was: group A, 9 class 0, 17 class 1, one class 2, and 2 class 3. Group B: 17 class 0, 10 class 1, 2 class 2, and one class 3. This difference was not statistically significant (P=.086). Only 3 cases were considered treatment failures, for a success rate of 93% in group A and 97% in group B. As a result of this pilot study, 500 cGy radiation treatment appears to be effective in the prevention of clinically significant heterotopic ossification after total hip arthroplasty.

Adult↗
PubMed2003

The use of a constrained acetabular component for recurrent dislocation.

The poor results of surgical treatment of chronic instability after total hip arthroplasty (THA) led to the development of a constrained acetabular component. In this study, 87 constrained THAs implanted for recurrent instability were reviewed retrospectively. Eighty-five hips were available for follow-up evaluation, with an average follow-up period of 58 months. These 85 hips were evaluated at a minimum of 3 years. Two recurrent dislocations were seen, caused by dissociation of the liner from the shell. Four acetabular components and 1 femoral component were revised. Overall, a 2.4% dislocation rate and an 8.2% revision rate were seen. The recurrent dislocation rate of 2.4% represents a significant improvement over other methods reported. Repeat dislocation was only seen in dissociation of cemented liners into well-fixed shells. We do not recommend this mode of fixation.

Acetabulum↗
PubMed2003

Femoral neck stress fractures: outcome analysis at minimum five-year follow-up.

INTRODUCTION: The complications associated with misdiagnosed or undertreated femoral neck stress fractures in young, active adults have been well documented in the orthopaedic literature. Less is known regarding the outcome of these injuries in patients whose diagnosis was timely and whose treatment was appropriate. METHODS: A sample of 25 patients previously involved in an unrelated study evaluating femoral neck stress fractures were contacted retrospectively 5 to 7 years after their injury. They were asked to complete a self-administered outcome evaluation, the Musculoskeletal Function Assessment (MFA), and answer several specific questions regarding their hips at the present time. Their MFA score was compared with treatment method, fracture type, and bone mineral density (BMD). RESULTS: All 25 patients responded to our inquiries. Of patients, 68% continued to feel "somewhat bothered" by their injury in at least one functional category. Nine patients felt "disabled." No patient has developed avascular necrosis, nonunion, malunion, or posttraumatic arthrosis or was currently under the care of an orthopaedic surgeon. Nine patients had developed stress fractures in other locations. The mean MFA score was 18.80 (range 0 to 63). A lower score corresponds to a patient's perceived higher level of function. Analysis of MFA scores did not reflect statistically significant differences between fracture location, treatment modality, or BMD. CONCLUSIONS: Femoral neck stress fractures can result in devastating problems for young adults. Appropriately treated patients, regardless of treatment method, may have persistent complaints.

Adolescent↗