Enyi Okereke

Longitudinal study of skeletal muscle adaptations during immobilization and rehabilitation.

This study describes the metabolic, morphologic, neurologic, and functional adaptations observed in the plantar flexors during 8 weeks of lower leg immobilization and 10 weeks of physical therapy following ankle surgery. A combination of magnetic resonance imaging and spectroscopy, isokinetic and isometric muscle testing, and simple functional tests revealed many adaptive changes due to immobilization, including atrophy, loss of muscle strength, reduced central activation, increase in fatigue resistance, and an increase in inorganic phosphate content. After 10 weeks of physical therapy all alterations were reversed, with the exception of a remaining 5.5% deficit in total muscle cross‐sectional area.

In vitro bone-cell response to a capacitively coupled electrical field. The role of field strength, pulse pattern, and duty cycle.

Newborn rat calvarial bone cells were grown to confluence and subjected to a matrix of sine wave 60-kHz capacitively coupled electrical signals of various field strengths, pulse-burst patterns, and duty cycles. Both [3H] thymidine incorporation into DNA and alkaline phosphatase activity were evaluated in field strengths ranging from 0.0001 to 20 mV/cm, with pulse-burst patterns ranging from continuous to 5 milliseconds ON/495 milliseconds OFF, with daily duty cycles ranging from 0.25% to 25%. A significant increase in proliferation occurred in field strengths of 0.1, 1, and 20 mV/cm when the signal was applied continuously for six hours. Significant proliferation also occurred when the 20-mV/cm field was pulsed for six hours at 5 milliseconds ON/495 milliseconds OFF and at 5 milliseconds ON/245 milliseconds OFF. No change in alkaline phosphatase activity occurred in the 20-mV/cm field with any signal. At 1 mV/cm, there was a significant decrease in alkaline phosphatase activity in the continuous signal and in the 5 milliseconds ON/62 milliseconds OFF signal; in the lower fields evaluated, there was an actual decrease in alkaline phosphatase activity with some of the signals. The field strength plays a dominant role in determining the bone-cells proliferative response, and to a lesser extent the alkaline phosphatase activity response, to a capacitively coupled electric field. The pulse configuration and the duty cycle are also important, but only if the proper field strength is being applied to the cell.

Nonoperatively Treated Displaced Bimalleolar and Trimalleolar Fractures: A 20-Year Follow-Up:

This study evaluates the long-term results of displaced bi- and trimalleolar fractures treated closed. Few reports exist in the literature regarding the long-term outcomes of ankle fractures, and none of these specifically addresses displaced bi- and trimalleolar fractures treated nonoperatively. This study analyzed the results of bi- and trimalleolar fractures treated by a single surgeon from 1973 to 1981. As was the standard of care at that time, these fractures were treated nonoperatively if a stable reduction was achieved and maintained. Serial radiographs confirmed the maintenance of reduction in a nonweightbearing long leg cast for 6 weeks and then a short leg walking cast for 6 weeks. Of the 34 patients in this series, 19 were available for review, 10 were deceased, and five were lost to follow-up. The average age at the time of injury was 39 years (range, 17–79 years), and the average length of follow-up was 20 years (range, 16–24 years). At the time of review, only two patients with trimalleolar fractures were minimally symptomatic or had radiographic evidence of mild degenerative changes. The average American Orthopaedic Foot and Ankle Score was 98 of 100 points (range, 87–100 points). This long-term follow-up shows that bi- and trimalleolar fractures can be treated nonoperatively if an anatomic reduction is maintained and closely followed. With reports indicating as much as a 5% deep infection rate and a 10% incidence of loss of reduction after internal fixation, universally recommending an operation for these injuries should be reconsidered, especially in high surgical risk patients.

Complete Atraumatic Rupture of the Flexor Hallucis Longus Tendon: A Case Report and Review of the Literature

A complete atraumatic rupture of the flexor hallucis longus tendon in a patient without systemic disease is a rare occurrence. Although four cases of complete traumatic ruptures have been cited in the literature, only one case of a complete atraumatic rupture has been previously reported. Presented here is a second case with a review of the literature and a discussion of the surgical indications.

Fibrodysplasia ossificans progressiva in two half-sisters: Evidence for maternal mosaicism

Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disorder of connective tissue characterized by congenital malformation of the great toes and by progressive heterotopic ossification of the soft tissues in specific anatomic and temporal patterns. We observed classic findings of FOP in 2 Native American half-sisters with the same unaffected mother and different unaffected fathers. This is the first report of FOP in sibs from different pregnancies with unaffected parents. The findings in this family indicate the possibility of maternal gonadal mosaicism in FOP and provide important new data for genetic counseling in this disease.

Subluxating Peroneal Tendon: Repair of Superior Peroneal Retinaculum Using a Retrofibular Periosteal Flap

This modification of a soft tissue reconstruction procedure for the treatment of peroneal tendon subluxation and dislocation consists of creating an anterior-based periosteal flap in the peroneal groove from the fibula. This flap is used to augment the superior peroneal retinaculum and prevent the anterior displacement of the peroneal tendons. Its multiple benefits include the augmentation of the anterior aspect of the superior peroneal retinaculum (which may be deficient) and the recreation of the normal anatomy with little disturbance of the surrounding tissue. This simple procedure, with its relative ease of reconstruction, can be performed quickly for patients with acute or chronic peroneal tendon subluxation.

3D stress MRI for studying the functional pathologies of the ankle complex

This project is a result of a marriage between two independent activities that existed for quite some time within two collaborative groups: (1) the development of a mechanical linkage device and its utilization to test externally the flexibility characteristics of the ankle complex under load; (2) the development of an MR imaging and image analysis methodology to characterize the internal 3D movements of bones of the ankle complex. In the resulting methodology, which we term stress MRI (sMRI for short), the ankle is MR imaged in various foot configurations while held in place by the linkage device with controlled load proven to detect hindfoot instability. Subsequently the acquired images are subjected to a series of image processing and analysis steps to yield a set of parameters to describe the morphology, architecture, and kinematics of the bones of the ankle complex. These parameters are computed from images acquired for 14 normal ankles (of 7 subjects, including the left and the right ankle) and for 8 cadaveric ankles, the latter in five different situations consisting of intact ankle, two ligaments - the CFL and ATFL - sectioned serially, and then after the two ligaments are surgically reconstructed by using two procedures. The results indicate that (i) there is considerable left-to-right symmetry in the ankles; (ii) ligament damage causes a few parameters to change significantly; (iii) both ankle and subtalar motions occur in inversion and anterior drawer; (iv) in vitro motion is generally greater than in vivo motion; (v) the surgical procedures are effective in achieving normalcy, yet there are differences in their performance.

3D kinematics of the tarsal joints from magnetic resonance images

We have developed a method for analyzing motion at skeletal joints based on the 3D reconstruction of magnetic resonance (MR) image data. Since the information about each voxel in MR images includes its location in the scanner, it follows that information is available for each organ whose 3D surface is computed from a series of MR slices. In addition, there is information on the shape and orientation of each organ, and the contact areas of adjacent bones. By collecting image data in different positions we can calculate the motion of the individual bones. We have used this method to study human foot bones, in order to understand normal and abnormal foot function. It has been used to evaluate patients with tarsal coalitions, various forms of pes planus, ankle sprains, and several other conditions. A newly described feature of this system is the ability to visualize the contact area at a joint, as determined by the region of minimum distance. The display of contact area helps understand abnormal joint function. Also, the use of 3D imaging reveals motions in joints which cannot otherwise be visualized, such as the subtalar joint, for more accurate diagnosis of joint injury.

Expanding the orthopaedist's role in the treatment of foot and ankle disorders

Many opportunities exist and more will become available for expanding the role of orthopaedic surgeons in the treatment of patients with foot and ankle conditions in the United States. The current authors present the main areas of opportunity: giving comprehensive foot care to patients who already are treated by orthopaedic surgeons and the application of advanced scientific biotechnology that will improve outcomes for patients with foot and ankle conditions who currently do not have satisfactory treatment. Orthopaedic surgeons must maintain a high level of commitment in their education and professional availability to patients and primary care physicians to expand their participation in foot and ankle care. Networking with physician and nonphysician primary care providers and volunteering educational services for fellow professionals in the evaluation and treatment of the entire spectrum of foot and ankle conditions is necessary. The general orthopaedist and the orthopaedic foot and ankle specialist can share in the future of treatment of patients with foot and ankle conditions in the United States.