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Biomedical subjects

David B Thordarson

Publications and source records attributed to David B Thordarson.

At least 19 recordsLinked to original sources
PubMed2006

Non-operative management of posterior tibialis tendon dysfunction: design of a randomized clinical trial [NCT00279630].

BACKGROUND: Posterior tibialis tendon dysfunction (PTTD) is a common cause of foot pain and dysfunction in adults. Clinical observations strongly suggest that the condition is progressive. There are currently no controlled studies evaluating the effectiveness of exercise, orthoses, or orthoses and exercise on Stage I or IIA PTTD. Our study will explore the effectiveness of an eccentric versus concentric strengthening intervention to results obtained with the use of orthoses alone. Findings from this study will guide the development of more efficacious PTTD intervention programs and contribute to enhanced function and quality of life in persons with posterior tibialis tendon dysfunction. METHODS/DESIGN: This paper presents the rationale and design for a randomized clinical trial evaluating the effectiveness of a treatment regime for the non-operative management of Stage I or IIA PTTD. DISCUSSION: We have presented the rationale and design for an RCT evaluating the effectiveness of a treatment regimen for the non-operative management of Stage I or IIA PTTD. The results of this trial will be presented as soon as they are available.

Adult↗
PubMed2006

Surgical management of insertional calcific achilles tendinosis with a central tendon splitting approach.

BACKGROUND: Insertional calcific Achilles tendinosis is a painful, frequently disabling condition. Numerous operative approaches for this problem have been described. This study evaluated the outcome of a central tendon splitting approach. METHODS: Twenty-two patients were evaluated after a central tendon splitting approach for persistent insertional calcific Achilles tendinosis. Followup averaged 34 (11 to 64) months. Suture anchors were routinely used to augment the tendon insertion after debridement. An American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score, shoewear comfort, and return to work were evaluated. A paired t-test was used to evaluate the results. RESULTS: Pain significantly improved from 7 points preoperatively to 33 points postoperatively (p < 0.001). Function improved significantly from 36 points to 46 points (p < 0.001). The ankle-hindfoot score improved from 53 points to 89 points (p < 0.001). Age older or younger than 50 years did not affect outcome. CONCLUSION: A central tendon splitting approach yielded good relief of pain with improved function, shoewear, and ability to work without painful postoperative scars.

Achilles Tendon↗
PubMed2006

Tibiotalocalcaneal arthrodesis using a dynamically locked retrograde intramedullary nail.

BACKGROUND: Tibiotalocalcaneal arthrodesis is an important salvage method for patients with complex hindfoot problems, including Charcot arthropathy, osteonecrosis of the talus, combined arthritis of the ankle and subtalar joint, and failed total ankle arthroplasty. This study evaluated the results of a dynamic retrograde intramedullary nail for fixation with posterior to anterior distal interlocking screws placed through the calcaneus for tibiotalocalcaneal fusion. METHODS: Thirty-three consecutive tibiotalocalcaneal fusions were done by a single surgeon (DBT) and were stabilized with a dynamic retrograde intramedullary nail. Time to fusion, impaction of the nail relative to the intramedullary canal, nail-tibial angle, and complications were noted. Average followup was 14 months. RESULTS: Twenty-nine of 33 feet (88%) fused at an average of 3.7 months after surgery. Average impaction of the nail was 2.3 (0.5 to 5.0) mm. Cortical hypertrophy at the tip of the rod or at the proximal interlocking screw was noted in 13 of 27 patients. A trend toward a higher nonunion rate was noted in patients with an increased nail-tibial angle. CONCLUSION: Dynamic retrograde intramedullary nailing for fixation of the tibiotalocalcaneal fusions is a good method of stabilizing this complex fusion construct.

Adult↗
PubMed2006

Results of step-cut medial malleolar osteotomy.

BACKGROUND: Treatment of certain complex ankle pathology, such as a talar body fracture or osteochondral lesion requiring grafting, can necessitate medial malleolar osteotomy for adequate operative exposure. This paper evaluates the step-cut medial malleolar osteotomy for exposure of the ankle joint. METHOD: Fourteen patients with intra-articular pathology, including talar body fractures or osteochondral lesions necessitating extensive intra-articular exposure had step-cut malleolar osteotomy. The average age of the patients was 37 (range 20-90) years, and the average followup was 8 months. RESULTS: All 14 patients had an uncomplicated intraoperative course, with excellent exposure of the ankle joint. All patients had prompt healing of the osteotomy by 6 weeks after surgery without loss of reduction. None of the patients had pain at the osteotomy site. CONCLUSIONS: Step-cut medial malleolar osteotomy is an excellent, reproducible method for extensive exposure of the talar dome.

Adult↗
PubMed2005

SRS cancellous bone cement augmentation of calcaneal fracture fixation.

BACKGROUND: The proper treatment of intraarticular calcaneal fractures remains controversial. The goal of operative treatment is to achieve anatomic reduction with stable internal fixation. One method for stabilizing fracture constructs is the use of calcium phosphate bone cement. The goal of this study was to evaluate a series of patients who had open reduction and internal fixation of intra-articular calcaneal fractures with calcium phosphate bone cement augmentation. METHODS: Fifteen patients had open reduction and internal fixation through an extensile lateral approach with standard low-profile hardware. The walls of the bone defect beneath the posterior facet were impacted with a curette and the void filled with SRS bone cement. Preoperative and postoperative plain radiographs and computed tomography (CT) were obtained on each patient. The most recent radiographs were assessed for maintenance of reduction. RESULTS: Nine patients were followed for an average of 13 (6 to 60) months. Six patients had less than 6 months followup. There were five type IIA, five type IIB, four type IIC, and one type IIIB-C fractures. All 15 fractures were noted on postoperative CT to have less than 2-mm of step-off with complete cement fill of the bony void. None of the patients developed a soft-tissue reaction to the cement. The first six patients were allowed to bear weight 6 weeks after injury, and the following nine patients were allowed to bear weight at 3 weeks after injury. No patient had any visible loss of reduction on most recent radiographs. Followup CT at 7 months in one patient and 12 and 51 months in another patient revealed no change in the bone-cement interface or amount of cement remaining. One patient's CT at 12 months revealed apparent fragmentation of the cement mass without loss of reduction. There was one major wound complication necessitating cement and hardware removal and free flap coverage. CONCLUSION: In this small series, patients had no evidence of soft-tissue reaction or loss of reduction with early weightbearing after open reduction and internal fixation augmented with calcium phosphate bone cement.

Adult↗
PubMed2005

Reliability of the Foot Function Index:: A report of the AOFAS Outcomes Committee..

BACKGROUND: There currently is no widely used, validated, self-administered instrument for measuring musculoskeletal functional status in individuals with nonsystemic foot disorders. The purpose of this paper was to report on the assessment of reliability of one of these instruments. We wanted to determine if the Foot Function Index (FFI), which has been validated in rheumatoid patients without fixed foot deformity or prior foot surgery, would be reliable for a population of patients with foot complaints without systemic disease. METHODS: Patients were recruited from five orthopaedic offices where the physicians were members of the American Orthopaedic Foot and Ankle Society. Patients were asked to complete the FFI at the time of their initial office visit and then were given a second copy to complete and return by mail 1 week after their visit. RESULTS: Ninety-six patients completed the first questionnaire, and 54 patients completed the second. Reliability in this population was acceptable with an average of 23.5% of the patients providing retest values within one point of the initial response and an average of 45.3% of the patients providing the same response, for a total of 68.8% of all respondents answering within one point between their initial and second questionnaire. In two of the three categories, there were frequent nonresponses or no applicable responses. Four questions, two in the pain section and two in the activity limitation section, generated 20% or more of the nonapplicable answers. CONCLUSIONS: The FFI appears to be a reasonable tool for low functioning individuals with foot disorders. It may not be appropriate for individuals who function at or above the level of independent activities of daily living.

Activities of Daily Living↗
PubMed2005

Effect of foot orthoses on tibialis posterior activation in persons with pes planus.

PURPOSE: To examine the influence of footwear on tibialis posterior (TP) activation in persons with pes planus. METHODS: Six asymptomatic adults with pes planus (arch index of < or =0.16) participated. Subjects performed a resisted foot adduction with plantar flexion exercise (3 sets of 30 repetitions). The exercise was performed barefoot and shod with foot orthoses. The two testing conditions were separated by a week. Magnetic resonance image signal intensity of the tibialis posterior, tibialis anterior, soleus, medial gastrocnemius, and peroneus longus was measured immediately before and after each exercise. Multivariate analyses of variance followed by paired Student's t-test were performed for the signal intensity of each muscle assessed to determine whether TP was selectively activated during the barefoot and shod exercises. RESULTS: When barefoot, five of the six subjects activated other lower-leg muscles in addition to TP. When wearing the foot orthoses and shoes, all five participants activated only TP. Additionally, activation of TP was higher when exercises were performed in shoes with orthoses than when barefoot (P = 0.019). CONCLUSION: Wearing the foot orthoses and shoes improved selective activation of the TP in persons with flat feet. In cases where selective activation of TP is desirable, such as persons with flat feet or TP tendon dysfunction, use of shoes and an arch supporting foot orthoses may enhance selective activation of the muscle.

Adult↗
PubMed2005

Age-adjusted baseline data for women with hallux valgus undergoing corrective surgery.

BACKGROUND: Functional and health-related quality-of-life data on a population of patients with hallux valgus are lacking. Similarly, the correlation of the severity of the deformity with these measures is unknown. METHODS: Two hundred and eighty-five women with an average age of forty-nine years who were scheduled for bunion surgery were enrolled in the study. The patients completed a baseline American Academy of Orthopaedic Surgeons (AAOS) foot and ankle outcomes questionnaire, which includes the Short Form-36 (SF-36) and a specific lower-extremity section on the foot and ankle. Preoperative radiographic data with regard to the hallux valgus angle and the intermetatarsal angle were stratified into groups according to the severity of the deformity (mild, moderate, or severe). The data were then stratified into age-groups consistent with those reported for the SF-36, and the results were compared with the SF-36 scores for the general population. The global foot and ankle score and the shoe comfort score were compared with general population scores that were published previously. The severity of the preoperative deformity was correlated with the baseline scores. RESULTS: General health scores were noted to be relatively stable throughout the age-groups for patients with bunions, with the older groups demonstrating better scores than the general population. Bodily pain scores were consistently worse for patients with a bunion through all age-groups compared with the general population. The average global foot and ankle score and the shoe comfort score were significantly lower (p < 0.001 for both) for the patients with a bunion than for the general population. The severity of the preoperative deformity did not correlate with any of the outcome scores. CONCLUSIONS: The bodily pain score from the SF-36 appears to be a sensitive measure of problems experienced by patients undergoing bunion surgery. Surprisingly, the severity of the deformity as measured radiographically did not correlate with any of the fifteen scores measured. These data may serve as a baseline for clinical hallux valgus studies with use of the SF-36 or the AAOS outcomes questionnaire.

Age Factors↗
PubMed2004

Débridement and primary closure of nonhealing foot wounds.

Fifty-eight chronic nonhealing foot wounds (51 patients) were treated with irrigation, aggressive débridement, and primary tension-free closure. Factors such as wound location, wound size, presence of infection, and healing outcome were recorded. In addition, medical comorbidities and preoperative laboratory test results were reviewed. Thirty-seven (64%) of the 58 wounds healed after primary closure. Of the other 21 wounds, 16 healed after repeat irrigation, debridement, and closure or local wound care; 2 patients were lost to follow-up after initial failed wound healing, 1 patient died after initial failed wound healing, and 2 cases were salvaged with amputation. Failed primary closures were thought not to increase wound size; all but 3 of these closures decreased wound size significantly. Differences between the wounds that healed primarily and the wounds that failed healing were not statistically significant. Diabetes was present in 46% of the patients whose wounds healed primarily versus 71% of the patients whose wounds failed healing (P = .06). Irrigation, débridement, and primary closure of nonhealing foot wounds can be a useful treatment option for most such patients. Complete healing or reduced wound size occurs in 95% of cases.

Chi-Square Distribution↗
PubMed2004

Infected fractures of the distal tibial metaphysis and plafond: achievement of limb salvage with free muscle flaps, bone grafting, and ankle fusion.

Infection after fractures of the tibial plafond is a challenging problem that may even result in amputation. The current study evaluates a limb salvage protocol and the associated long term functional outcome in 6 patients (mean age 46 years) who were treated for infection after a fracture of the distal tibial metaphysis and plafond. Our limb salvage protocol included 3 stages: 1) radical debridement and stabilization of the ankle with a bridging external fixator, 2) soft tissue coverage with free muscle flaps, and 3) ankle fusion using iliac crest bone graft for filling the existing defects measuring 4.2 cm on average. At a mean followup of 5.5 years (range, 2-10.5 years), limb-salvage and eradication of infection was accomplished in all extremities. Fusion of the ankle joint was achieved in all patients, with one patient requiring a supplemental bone grafting procedure for delayed healing of the fusion site. All patients are able to walk without assistive devices and five of six patients are pain free. Limb salvage with free muscle flaps, bone grafting, and ankle fusion is a viable option for the treatment of infected tibial metaphysis and plafond fractures.

Adult↗
PubMed2003

Open reduction and internal fixation of calcaneal fractures with a low profile titanium calcaneal perimeter plate.

Forty-two intra-articular calcaneus fractures underwent open reduction and internal fixation with a low profile, titanium plate with a shape similar to the lateral aspect of the calcaneus. All 42 fractures healed without complication. There were no cases of hardware breakage. None of the patients were noted to have a loss of reduction. The plates were applied without bending and molded to the side of the calcaneus with tightening of the screws. No patient complained of symptomatic hardware during the follow-up period. With postoperative plain radiographs, the reduction was judged as anatomic in 35 patients, less than a 2 mm step off in six patients, and one patient with greater than 2 mm step off. Use of this new plate allows for easy application as it does not require contouring, is well tolerated without complaints of hardware prominence, and none of the hardware broke prior to fracture union.

Adolescent↗
PubMed2003

The association between diagnosis of plantar fasciitis and Windlass test results.

Twenty-two patients with plantar fasciitis, 23 patients with other types of foot pain, and 30 patients in a control group were evaluated with the Windlass test performed in a weightbearing and non-weightbearing position. In the non-weightbearing test, the first MP joint was maximally dorsiflexed with the ankle stabilized. The weightbearing test was performed with the toes hanging off the edge of a stool and dorsiflexion of the first MP was performed. Seven of the 22 patients in the plantar fasciitis group had a positive weightbearing Windlass test (31.8%), while only three had a positive test result in a non-weightbearing position (13.6%). None of the patients in the other foot pain group or control group had pain in the weightbearing and non-weightbearing positions. Despite its high rate of specificity, the low rate of sensitivity of the Windlass test may limit its usefulness in the clinical evaluation in patients with plantar fasciitis.

Fasciitis, Plantar↗
PubMed2003

Use of demineralized bone matrix in ankle/hindfoot fusion.

Sixty-three patients who underwent complex ankle or hindfoot fusion had demineralized bone matrix placed in their fusion site to stimulate fusion. Thirty-seven patients had Grafton putty, a demineralized bone matrix product, and 26 patients had Orthoblast, a demineralized bone matrix mixed with crushed cancellous allograft bone placed to stimulate their fusion site. All patients were followed clinically and radiographically to fusion or nonunion. Of the 37 patients who had Grafton putty placed to stimulate ankle or hindfoot fusion, five (14%) developed a nonunion. Of the 26 patients who had Orthoblast placed to stimulate fusion, two (8%) developed a nonunion. These differences were not statistically significant. Nonunion rates of approximately 10% continue to be reported for ankle and hindfoot fusion procedures. In an attempt to minimize this complication, various bone graft substitutes have been used. We found no difference in efficacy of the two demineralized bone matrix compounds, and were not able to demonstrate a superior union rate compared to historical controls.

Adult↗
PubMed2003

Position of the distal fibular fragment in pronation and supination ankle fractures: a CT evaluation.

BACKGROUND: Although classically the fibula has been reported to be in external rotation after supination-external rotation (SER) or pronation-external rotation (PER) ankle fractures, a previous CT study demonstrated that what had traditionally been interpreted as external rotation of the distal fibular fracture fragment is actually internal rotation of the proximal fibular fragment. The purpose of this study was to evaluate a series of CT scans in patients who have suffered type IV SER or PER ankle fractures to assess the rotational deformity of the fibular fragment. MATERIALS AND METHODS: CT scans of the injured and uninjured extremities were performed on 30 extremities which had sustained either SER (21) or PER (9) injuries. The rotational relationship between the tibia and fibula was determined by a measured rotational ratio. A qualitative assessment of the rotational relationship between the tibia and fibula above, at, and below the fracture site at the level of the mortise was also performed. The difference in the ratio (calculated by subtracting the rotation ratio of the normal side from the fracture side) demonstrated whether the fractured fibula is externally or internally rotated compared to the uninjured side. RESULTS: The average rotational ratio difference above the fracture compared to below the fracture for the SER group demonstrated significant external rotation (p < .001). The PER fracture also demonstrated external rotation of the distal fragment compared to the proximal fragment (p = .002). Additionally, qualitative assessment of the relationship demonstrated no obvious change in the rotational relationship in any patient above the fracture site except one where mild internal rotation of the proximal fragment was noted. However, at the level of the mortise, all had a normal talofibular rotational relationship while 24 of 30 had widening of the medial clear space with external rotation clearly evident on 15 of these 24 scans. CONCLUSION: Our study demonstrated that the distal fibular fragment in both SER and PER fractures is externally rotated relative to both the contralateral normal side and compared to the proximal fibular fragment.

Adult↗
PubMed2003

Ingrowth of bone into absorbable bone cement: an in vivo microscopic evaluation.

The purpose of the study reported here was to use an in vivo rabbit model to evaluate the rate of bone ingrowth into remodelable calcium phosphate bone cement. We evaluated an in vivo bone chamber placed in a rabbit tibia with its ingrowth compartment filled with absorbable calcium phosphate bone cement (Norian Skeletal Repair System; Norian Corp, Cupertino, Calif). Five New England white rabbits had a single bone chamber implanted into the proximal right tibia. Observations were made and photomicrographs taken on a weekly basis. Results of morphological analysis showed sequential loss of cement and subsequent bone ingrowth over a testing period of up to 30 weeks. Resorption of bone cement was complete in 1 rabbit. The other rabbits had significant bone ingrowth, which reaffirms the biocompatibility of this material. Results of this study showed that using in vivo microscopy with the rabbit bone chamber model was useful in evaluating bone ingrowth and replacement of absorbable bone cement. This model may make it possible to evaluate various combinations of bone cement and bone growth factors, which could serve as an alternative to autogenous bone grafting.

Animals↗
PubMed2002

Medial eminence thickness with and without hallux valgus.

The purpose of this study was to determine if hypertrophy of the medial eminence occurs in patients with hallux valgus. Thirty-three patients (50 consecutive feet) who underwent surgical correction for hallux valgus were evaluated. They had preoperative and postoperative radiographs. The hallux valgus angle, intermetatarsal angle and size of the medial eminence were recorded. The same measurements were then obtained from the radiographs of 50 randomly selected, age-matched controls with a hallux valgus angle less than 15 degrees and intermetatarsal less than 9 degrees. The average width of the medial eminence was 4.4 mm in the hallux valgus group and 4.1 mm in the control group. In most patients, hypertrophy of the medial eminence is not a component of the pathology.

Case-Control Studies↗