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Biomedical subjects

James A Nunley

Publications and source records attributed to James A Nunley.

At least 19 recordsLinked to original sources
PubMed2006

The reliability and reproducibility of foot type measurements using a mirrored foot photo box and digital photography compared to caliper measurements.

UNLABELLED: The height of the medial longitudinal arch (MLA) is thought to be a predisposing factor to various lower extremity injuries. Discrepancy exists as to whether MLA height plays a role in injury prevention. The purpose of this study was to determine the intertester and intratester reliability, and the validity of the mirrored foot photo box (MFPB) and caliper measurements to radiographic measurements. METHODS: Thirty subjects with equal numbers of men and women were recruited. Both feet were tested (n=60) in a 90% weight bearing stance. A set of anatomic landmarks were palpated, marked, and measured using a caliper, MFPB, and radiographs. The protocol was completed by two testers on 2 days approximately 1 week apart. Intertester and intratester reliability were determined using the intraclass correlation coefficient (ICC)(2,k) and the ICC(2,1), respectively. Validity of both measurement techniques to radiographic measurements was determined using the ICC(2,k). RESULTS: The intertester reliability ranged from 0.991 to 0.577, while the intratester reliability ranged from 0.994 to 0.527, with first metatarsal angle being the only variable with poor reliability. Most variables demonstrated acceptable validity between the MFPB and the caliper measurements, and acceptable validity between the MFPB and calipers compared to radiographic measurements. The MFPB took 51.3+/-19.6s per foot while the caliper measurements averaged 227.4+/-68.9s to complete the measurements. DISCUSSION: The MFPB is as reliable as the caliper measurements, and offers better intertester reliability. Both the caliper and MFPB measurements demonstrated acceptable validity to radiographic measurements and testing time was reduced when using the MFPB compared to calipers.

Adolescent↗
PubMed2006

Composition and transport properties of human ankle and knee cartilage.

The incidence of osteoarthritis is significantly higher in the knee as compared to the ankle, suggesting that differences in the properties of cartilage from these joints may contribute to the development of osteoarthritis. As an avascular tissue, articular cartilage depends primarily upon diffusion for molecular transport. The goal of this study was to determine if differences in the structure and composition between ankle and knee cartilage were also reflected as differences in solute transport properties. The diffusion coefficient and partition coefficient of a 70-kDa dextran molecule were measured in human ankle and knee articular cartilage using fluorescence recovery after photobleaching (FRAP) and were compared to the proteoglycan, collagen, water, and DNA contents within each zone. The mean partition coefficient was significantly lower in the ankle compared to the knee (0.010+/-0.002 vs. 0.022+/-0.003, p<0.01), but no differences in the diffusion coefficients were observed (34.6 +/- 0.9 microm(2)s(-1) vs. 35.4+/-2.4 microm(2)s(-1), p=0.70). Ankle cartilage exhibited higher proteoglycan content as well as a trend toward lower water content, suggesting that ankle cartilage has a smaller effective pore size than knee cartilage. These findings suggest that differences in the composition of ankle and knee cartilage contribute to a difference in the partition coefficient. The results of this study provide further support for the hypothesis that the transport properties of cartilage may play a role in the differences in the incidence of osteoarthritis in these joints by altering the effective concentration of growth factors and cytokines to which chondrocytes are exposed.

Ankle Joint↗
PubMed2006

Extensor retinaculum augmentation reinforces anterior talofibular ligament repair.

Repair of the anterior talofibular ligament often is augmented with the inferior extensor retinaculum because it is thought to reinforce the primary ligament repair. The additional dissection and suturing extend the duration of surgery, and not all surgeons routinely include inferior extensor retinaculum augmentation in anterior talofibular ligament repairs. To determine whether there is a reasonable basis for this surgery, we ascertained the degree to which inferior extensor retinaculum augmentation reinforced the primary anterior talofibular ligament repair. Matched pairs of cadaveric ankles had controlled inversion while monitoring resistance to inversion, first with the anterior talofibular ligament sectioned, then with primary anterior talofibular ligament repair alone or with inferior extensor retinaculum augmentation. The resistance to ankle inversion was greater at 5 degrees, 10 degrees, 15 degrees, 20 degrees, and 25 degrees rotation in ankles that had inferior extensor retinaculum augmentation. Anterior talofibular ligament failure occurred at similar inversion angles in both treatment groups, but the primary anterior talofibular ligament repair required more torque to fail in the augmented group. With these ankle loading conditions, inferior extensor retinaculum augmentation provided protection to the primary anterior talofibular ligament repair, indicating that broader clinical use of augmentation may be warranted.

Adolescent↗
PubMed2006

Bending stiffness and pull-out strength of tapered, variable pitch screws, and 6.5-mm cancellous screws in acute Jones fractures.

BACKGROUND: Stabilization of fifth metatarsal Jones fractures with intramedullary screws is popular, particularly in athletes, because nonoperative treatment involves prolonged casting and a distinct risk of nonunion or delayed union. Conventional lag screws of various diameters are routinely used for Jones fracture fixation. More recently, tapered, headless, variable pitch screws have become available as an option. These screws have the advantage of not having a protruding screw head, but information regarding their performance in Jones fracture fixation is limited. To determine whether differences exist in the mechanical integrity of fifth metatarsals fixed with each type of screw, this study was designed to compare Jones fracture fixation with 6.5-mm partially-threaded lag screws and headless, tapered, variable pitch compression screws with a 4-mm leading-thread diameter and 5-mm trailing-thread diameter. METHODS: Simulated Jones fractures were created in 20 matched pairs of fresh-frozen fifth metatarsals. One bone from each pair was stabilized with a tapered, variable pitch screw, and the contralateral with a 6.5-mm partially-threaded cancellous lag screw. The stiffness in lateral-to-medial bending of the resulting constructs and the resistance of the screws to pulling out of the distal fragment were quantified. RESULTS: There was no demonstrable difference in bending stiffness between metatarsals fixed with the two types of screws (p = 0.688). The 6.5-mm screw provided significantly higher resistance to pull-out (p = 0.001). CONCLUSIONS: Headless, tapered, variable pitch compression screws of the size tested are not entirely comparable to 6.5-mm lag screws in this application. They are effective in resisting bending but do not offer equivalent resistance to thread pull-out.

Aged↗
PubMed2006

Posttraumatic proximal interphalangeal joint flexion contractures.

Normal motion of the proximal interphalangeal joint requires bony support, intact articular surfaces, unimpeded tendon gliding, and uncompromised integrity of the collateral ligaments and volar plate. Deficiency in any one of these structural requirements can lead to a loss of finger joint motion and decreased hand function. Once finger extension is lost, options include nonsurgical or surgical treatment. Nonsurgical treatment such as splinting or serial casting should be tried before attempting surgical intervention. When severe flexion deformity exists or the vascular status of the finger has been compromised, arthrodesis or amputation should be undertaken instead of procedures to regain motion. Surgical options for regaining motion include external fixators and open surgical release. Although they can lead to improved extension at the proximal interphalangeal joint, external fixators carry a risk of reduced finger flexion and pin site infection. Most clinical series of patients who have undergone surgical release document improvement in flexion contracture between 25 degrees to 30 degrees and a shift of the flexion/extension arc into a more functional range. Close follow-up after surgery is warranted, with frequent physical therapy and splinting.

Contracture↗
PubMed2005

The effects of exogenous nitric oxide donor on motor functional recovery of reperfused peripheral nerve.

PURPOSE: To investigate the effects of the nitric oxide donor S-nitroso-N-acetylcysteine (SNAC) on motor functional recovery of reperfused rat sciatic nerve. METHODS: Seventy-eight rats were divided into groups treated with SNAC (100 nmol/100 g/min), methylprednisolone 30 mg/kg/h for 15 minutes, 45-minute pause, 5.4 mg/kg/h for 1.5 h), and phosphate-buffered saline 0.2 mL/100 g/h). A 1-cm segment of sciatic nerve had 2 hours of ischemia and the results were evaluated after various reperfusion periods using a walking track test, muscle contractile testing, muscle weight, and histology. RESULTS: During reperfusion there was a significant overall improvement in sciatic functional index measurement and isometric titanic contractile force for the SNAC-treated group compared with the methylprednisolone- and phosphate-buffered saline- treated groups. The SNAC group had significantly earlier improvement in the sciatic functional index measurement between days 7 and 28. Restoration of the contractile force and muscle weight of the extensor digitorum longus muscle began earlier in the SNAC group--after day 11--whereas the other 2 groups showed progressive atrophy until day 21, with a significant difference between the SNAC group and the other 2 groups. Histologic examination showed that SNAC-treated rats had less severe degeneration and earlier regeneration of axons than the others. Although methylprednisolone-treated rats showed earlier recovery than phosphate-buffered saline-treated rats in all parameters there were no significant differences between these 2 groups. CONCLUSIONS: Supplementation of nitric oxide is effective in promoting motor functional recovery of the reperfused peripheral nerve and has potential to replace or augment steroids as therapeutic agents in treatment of nervous system ischemia/reperfusion injury.

Acetylcysteine↗
PubMed2005

The impact of diabetes on patient outcomes after ankle fracture.

BACKGROUND: Ankle fracture is one of the most common injuries treated by orthopaedic surgeons, and the presence of diabetes complicates treatment and recovery from this injury. Although a higher prevalence of adverse postoperative events has been found in small series of diabetic patients with an ankle fracture, we are not aware of any large national series with specific documentation of the outcomes following ankle fracture in patients with diabetes. METHODS: We analyzed data from the Nationwide Inpatient Sample database for the years 1988 through 2000. Information regarding the hospitalizations of 160,598 adult patients with an ankle fracture who underwent subsequent surgical procedures was extracted from the database. Multiple linear and logistic regression models were used to ascertain whether patients with diabetes mellitus were more likely than patients without diabetes mellitus to die while in the hospital, to have in-hospital postoperative complications, to stay longer in the hospital, to have a higher incidence of non-routine discharge, and to have a higher total cost associated with the hospital stay. RESULTS: Significant increases in in-hospital mortality, the rate of in-hospital postoperative complications, the length of hospital stay, the rate of non-routine discharge, and the total charges were found in the diabetic patient group (p < 0.001). Specifically, we found that diabetic patients across all levels of fracture severity (closed unimalleolar, closed bimalleolar or trimalleolar, and dislocated or open fractures) stayed in the hospital for about one additional day (mean, 4.7 compared with 3.6 days) and incurred more than dollar 2000 in increased charges (mean, dollar 12,898 compared with dollar 10,794). CONCLUSIONS: This nationally representative study of inpatients in the United States provides evidence that diabetic patients with an operatively treated ankle fracture are likely to have worse results than non-diabetic patients with regard to postoperative complications, mortality, rate of non-routine discharge, length of hospital stay, and total hospital charges.

Ankle Injuries↗
PubMed2005

MRI of spring ligament tears.

OBJECTIVE: Surgical repair of the spring ligament is becoming recognized as an important management component of adult-acquired flatfoot, yet little literature exists on the MRI appearance of spring ligament abnormalities. In this article, we describe the MRI appearance of surgically proven spring ligament tears. CONCLUSION: MRI findings present in surgically proven spring ligament tears include an abnormal spring ligament caliber, signal intensity, waviness, a full-thickness gap, and posterior tibial tendonopathy. The finding unique to cases with surgically proven tears is a full-thickness gap in the ligament, seen in 79% of the cases in our series. When multiple abnormalities are seen in the spring ligament in conjunction with a full-thickness gap, the diagnosis of a tear can be made with confidence.

Adult↗
PubMed2004

Avascular necrosis of the talus: current treatment options.

AVN of the talus is a challenging disease process with respect to patho-physiology and treatment. We believe that our algorithm is a legitimate approach to aid the orthopedic surgeon in initiating a promising treatment. It is divided into different levels and allows to change between some. This is not the only way to proceed but it seems promising, especially if the long-term results with the vascularized bone grafts show revascularization of the talus. As always in medicine, the treatment needs to be individualized. Arthrodesis always should be the last option and is a challenging procedure.

Adult↗
PubMed2004

Open calcaneal fractures: results of operative treatment.

OBJECTIVE: To review our series of open calcaneal fractures compared with other series. DESIGN: Retrospective review. SETTING: All patients were treated at a single Level 1 trauma center. PATIENTS/PARTICIPANTS: We reviewed 19 consecutive patients, each with an open fracture of the calcaneus. Fracture morphology ranged from Sanders type II to type IV; associated soft tissue injuries were variable, ranging from Gustilo type I to type IIIC. INTERVENTION: All patients were treated with intravenous antibiotics, tetanus prophylaxis, and immediate and repeat irrigation and debridement. Definitive fracture reduction was performed at an average of 7 days after injury (range 0-22 days). Fixation methods included lateral plate and screws (11), Kirschner wires and/or screws (6), or none (2). MAIN OUTCOME MEASUREMENTS: AOFAS ankle-hindfoot scores, clinical examination, and radiographs. RESULTS: All 19 patients were available for follow-up with a physical examination and radiographs at an average of 26.2 months. The AOFAS ankle-hindfoot scores averaged 81.6 (range 58-94). Five patients required free tissue transfer for wound coverage. Two patients developed chronic, draining calcaneal osteomyelitis, for which one patient underwent a below-knee amputation. In our series, for the patients with Gustilo type II and type III open calcaneal fractures, there was an 11% complication rate with higher than expected health-related quality-of-life indices. CONCLUSIONS: Our findings do not reflect as high a complication rate for open calcaneal fractures as previously reported. We support previous claims that definitive hardware placement at the time of initial irrigation and debridement probably is not warranted: Definitive fracture stabilization can and should wait until soft tissue coverage is fully assessed.

Adolescent↗
PubMed2004

Torsional strains in the proximal fifth metatarsal: implications for Jones and stress fracture management.

BACKGROUND: Reports of nonunion of proximal fifth metatarsal fractures treated by internal fixation indicate that current fixation methods do not always adequately address the stresses to which the bone is subjected during ambulation. In particular, the insertion sites of the peroneus brevis and peroneus tertius tendons on the fifth metatarsal suggest that their actions can impose torsional stresses on the areas of the bone in which Jones fractures and stress fractures occur. Intramedullary screw fixation, however, offers little resistance to rotation of the proximal and distal fragments relative to one another. METHODS: To determine the potential for the existence of torsional stresses in the fifth metatarsal during post-operative ambulation, a simplified cadaver model of single-limb stance was used in which cadaver feet were subjected to concurrent axial and tendon forces while monitoring the outputs of stacked rosette strain gauges placed at the typical sites of Jones and stress fractures. Principal strain and shear strain magnitudes and directions were measured. RESULTS: The shear strain magnitudes and strain axis directions indicated the presence of torsional stresses in the underlying bone potentially capable of causing internal rotation of the proximal fragment relative to the distal end of the bone. CONCLUSIONS: This finding has implications for the treatment of both Jones fractures and stress fractures of the proximal fifth metatarsal. An internal fixation device that has the capability to resist torsion as well as tension and bending would appear optimal to treat these fractures.

Adult↗
PubMed2004

Torque resistance after fixation of Jones fractures with intramedullary screws.

BACKGROUND: Intramedullary screws frequently are used for fixation of Jones fractures of the fifth metarsal. While the ability of intramedullary screw fixation in fifth metatarsals to resist bending and tensile forces is well known, the ability to withstand torsion has not been studied. This paper compares the torsional stiffness of Jones fractures treated with 6.5-mm short- threaded intramedullary screws to those treated with 5.0-mm cannulated short-threaded intramedullary screws. METHODS: Nine fresh-frozen, matched pairs of cadaver fifth metatarsals had an acute Jones fracture simulated with an osteotomy. They were stabilized with intramedullary screws and then loaded to failure. RESULTS: The torsional stiffness of the metatarsals fixed with the 6.5-mm did not differ significantly from that using 5.0-mm screws. However, to achieve stability, the 5.0-mm screw had to be long enough to reach the metatarsal head and neck. This tended to straighten the normally curved fifth metatarsal bone and caused lateral gapping at the fracture site. CONCLUSION: Both 5.0-mm or 6.5-mm screws provide equal torsional rigidity, but 5.0-mm screws may need to be longer, which could potentially straighten the fifth metatarsal shaft in patients who have a curved fifth metatarsal.

Aged↗
PubMed2004

Potential donor rotational bone grafts using vascular territories in the foot and ankle.

BACKGROUND: An improved understanding of the extraosseous and intraosseous blood supply of the distal aspect of the tibia, distal aspect of the fibula, cuboid, and cuneiforms should identify vascular territories that would enable surgeons to perform rotational vascularized pedicle bone-grafting procedures in the foot and ankle. METHODS: We investigated the blood supply of twenty cadaveric lower extremities using two vascular injection techniques. In order to define the extraosseous and intraosseous arterial anatomy in this region, ten specimens were sequentially subjected to injection with Batson's compound, soft-tissue digestion, and bone-clearing according to a modified Spalteholz technique. To further characterize the extraosseous vascular anatomy, the other ten specimens were injected with latex and dissected. RESULTS: We identified a consistent and previously unnamed blood supply to the distal aspect of the tibia, distal aspect of the fibula, cuboid, and cuneiforms. Four vessels, each present in all of our specimens, provided distinct vascular territories to bone. A branch of the proximal lateral tarsal artery supplied a consistent vascular territory in the cuboid with an average of fifteen nutrient vessels. Similarly, a branch of the distal medial tarsal artery to the first cuneiform supplied an average of nine nutrient vessels superior to the tibialis anterior tendon insertion. A branch of the anterior lateral malleolar artery to the fibula supplied an average of seven nutrient vessels to the lateral malleolus. A branch of the distal lateral tarsal artery provided the midsection of the third cuneiform with an average of seven nutrient vessels. In the latex-injected specimens, harvesting of the vascularized pedicle bone grafts designed from these data demonstrated their anatomic plausibility and arcs of rotation. CONCLUSIONS: Four new rotational vascularized pedicle bone grafts have been identified in the foot and ankle. These grafts were present in all of our specimens, were well vascularized, had wide arcs of rotation, and were relatively easy to harvest.

Aged↗
PubMed2004

Ankle arthrodesis.

This review article deals with ankle fusions, their indications, preoperative assessment, surgical technique, and postoperative treatment along with a discussion of complications and long-term results.

Ankle Joint↗
PubMed2004

Ulnohumeral arthroplasty.

Seven patients underwent 9 ulnohumeral arthroplasties for degenerative arthritis of the elbow. At mean follow-up of 26 months, 5 elbows were pain free; two continued to cause mild pain and one to cause moderate pain. Extension improved from 22 degrees+/-8 degrees preoperatively to 12 degrees+/-9 degrees postoperatively (p=0.02); the average correction was 10 degrees+/-10 degrees. Flexion improved from 122 degrees+/-8 degrees to 133 degrees +/- 8 degrees (p=0.02); the average correction was 11 degrees+/-11 degrees. One patient had a late supracondylar humerus fracture which healed well with open reduction and internal fixation. Overall, we believe that ulnohumeral arthroplasty is relatively safe and easy to perform. Our patients did have modest improvements in range of motion, but complete relief of pain occurred in only about two thirds of the patients.

Adult↗
PubMed2004

Xanthogranuloma of the sciatic nerve: case report.

OBJECTIVE AND IMPORTANCE: Xanthogranulomas involving the central or peripheral nervous system are extraordinarily rare. None have been reported in the lower extremity. Here, we report and characterize the first case of xanthogranuloma of the sciatic nerve. CLINICAL PRESENTATION: A 58-year-old woman presented with poorly localized right back and groin pain. Magnetic resonance imaging studies revealed an enhancing lesion of the sciatic nerve in the right gluteal region. INTERVENTION: The sciatic nerve xanthogranuloma was resected without complication. CONCLUSION: Our report indicates that xanthogranuloma, although extremely rare, may occur throughout the nervous system. Our evaluation demonstrates that such lesions involving the peripheral nervous system have similar pathological characteristics to xanthogranulomas that more commonly occur in the skin.

Female↗