Biomedical subjects

Richard M Marks

Publications and source records attributed to Richard M Marks.

7 recordsLinked to original sources

PubMed2007

Kinematic changes of the foot and ankle in patients with systemic rheumatoid arthritis and forefoot deformity.

Minimal published data exist characterizing the effect of rheumatoid arthritis of the forefoot (RA) on multi-segmental gait kinematics. The purpose of this study was to examine specific changes in segmental foot motion in patients with RA as compared to persons without foot/ankle pathology. This was a cross-sectional, descriptive study consisting of 22 preoperative adult patients (29 feet) diagnosed with RA and 25 adult patients with no known foot pathology (Control). All RA patients were evaluated by the same orthopaedic surgeon. This group consisted of 20 women and 2 men with a mean age of 54 years (range, 17-76 years). The Control cohort consisted of 13 men and 12 women with a mean age of 41 years (range, 27-73 years). Foot and ankle motion data for the RA population were obtained using a 15-camera Vicon Motion Analysis System (Vicon Motion Systems, Inc., Lake Forest, CA). Anterior-posterior, lateral, and modified coronal radiographic views were obtained to relate marker position to underlying bony anatomy. Temporal and three-dimensional kinematic parameters were obtained via the 4-segment Milwaukee Foot Model. Quantitative comparisons of range of motion values during the seven phases of gait were made between RA and Control ankles using unpaired nonparametric methods. The RA group showed significant differences (p < 0.001) as compared to Controls with prolonged stance time, shortened stride length, increased cadence, and a walking speed that was 80% of Control. Overall, kinematic data in the RA cohort showed significant differences (p < 0.001) in motion for tibial, hindfoot, and forefoot motion as compared to Controls. The effect of RA on segmental foot motion is poorly understood. This study characterized the effect that RA has on motion about the foot and ankle during gait, providing insight into this pathology to improve quantitative assessment, treatment planning, and rehabilitative care.

Adult↗

PubMed2005

Preoperative gait characterization of patients with ankle arthrosis.

The purpose of this study was to evaluate the kinematic changes that occur about the foot and ankle during gait in patients with degenerative joint disease (DJD). By comparing a normal adult population with what was found in the DJD population we determined how the motion of theses groups differed, thereby characterizing how this pathology affects foot and ankle motion. A 15-camera Vicon Motion Analysis System was used in conjunction with weight bearing radiographs to obtain three-dimensional motion of the foot and ankle during ambulation. The study was comprised of 34 patients and 35 ankles diagnosed with DJD (19 men and 15 women) of the ankle and 25 patients with normal ankles (13 men and 12 women). Dynamic foot and ankle motion was analyzed using the four-segment Milwaukee Foot Model (MFM). The data from this model resulted in three-dimensional (3D) kinematic parameters in the sagittal, coronal, and transverse planes as well as spatial-temporal parameters. Patient health status was evaluated using the SF-36 Health Survey and American Orthopaedics Foot and Ankle Society (AOFAS) hindfoot scores. The DJD group showed significant differences (p<0.001) as compared to normals with prolonged stance time, shortened stride length, reduced cadence and a walking speed which was only 66.96% of normal. Overall, kinematic data in the DJD cohort showed significant differences (p<0.001) in all planes of motion for tibial, hindfoot and forefoot motion as compared to normals. The average preoperative AOFAS hindfoot score was 26. DJD of the ankle results in decreased range of motion during gait. This decreased range of motion may be related to several factors including bony deformity, muscle weakness, and attempts to decrease the pain associated with weight bearing. To date there has not been a study which describes the effect of this disease process on motion of the foot and ankle. These findings may prove to be useful in the pre-operative assessment of these patients.

Adult↗

PubMed2005

Arthrodesis of the first metatarsophalangeal joint.

Arthrodesis of the first metatarsophalangeal joint is indicated in patients with symptomatic arthrodesis or advanced hallux valgus deformities that are unresponsive to nonsurgical treatment. Several fixation techniques have been described, including intefragmentary compression screws and/or dorsal plate fixation. Using these modern fixation techniques, the rate of fusion is between 94% to 98%, with high patient satisfaction. Appropriate positioning of the fusion is important for satisfactory outcome.

Arthrodesis↗

PubMed2004

Imaging of the navicular.

This article presented a rational approach to imaging of navicular pathology. The indications, techniques, and limitations of conventional radiographic imaging were discussed. In addition, the role of advanced imaging techniques, including MRI, CT, and NMI, in the diagnosis of navicular pathology was presented. By appropriately combining plain radiographic imaging with advanced imaging modalities, an accurate diagnosis is typically obtained.

Acute Disease↗

PubMed2004

Validation of a multisegment foot and ankle kinematic model for pediatric gait.

This paper reports the development, accuracy, reliability, and validation protocol of a four-segment pediatric foot and ankle model. The four rigid body segments include: 1) tibia and fibula; 2) hindfoot--talus, navicular, and calcaneus; 3) forefoot--cuboid, cuneiforms, and metatarsals; and 4) hallux. A series of Euler rotations compute relative angles between segments. Validation protocol incorporates linear and angular testing for accuracy and reliability. Linear static system resolution is greatest in the Y orientation at 0.10 +/- 0.14 mm and 0.05 level of significance and 99.96% accuracy. Dynamic linear resolution and accuracy are 0.43 +/- 0.39 mm and 99.8%, respectively. Angular dynamic resolution computes to 0.52 +/- 3.36 degrees at 99.6% accuracy. These calculations are comparable to the Milwaukee adult foot and ankle model.

Ankle↗

PubMed2004

Glomus tumor of the hallux: case presentation and review of the literature.

Glomus tumor is an unusual benign neoplasm of the extremity. Although it is most commonly found as a painful subungual lesion in the digits of the hand, the diagnosis has been reported at various sites throughout the lower extremity. Presented is a glomus tumor of the hallux with correlative imaging and surgical findings, including a review of the literature.

Adult↗

PubMed2003

Medial-sided bony procedures: why, what, and how?

The adult acquired flat foot deformity is a common clinical entity; rupture or incompetence of the posterior tibial tendon is a frequent cause. The natural history is characterized by progressively worsening deformity and early recognition is important. Nonoperative treatment can alleviate symptoms and control progression in nearly all stages of the disease. Should this fail to control symptoms or prevent progression of deformity, operative intervention should be considered. In stage I disease, exploration and debridement, with or without FDL tendon transfer, is a viable option. In stage II disease, the PTT becomes elongated and the medial soft tissues become attenuated. Exploration and debridement of the PTT is performed, but frequently a FDL tendon transfer or side-to-side anastomosis is required. It has been shown that soft tissue procedures alone may fail to correct deformity and this can lead to deterioration of results over time. Combined procedures, including soft tissue reconstructions to restore PTT function and bony procedures to correct deformity, have become popular. When the PTT is intact and degeneration or elongation is minimal, as in stage I or early stage II disease, reconstruction of the medial column with advancement of an osteoperiosteal flap based on the PTT insertion, combined with selective arthrodeses of the medial column, may be considered. These procedures have been well described for the treatment of symptomatic flexible flat foot in children and adolescents but experience in adults is lacking. Although it may be theoretically possible to passively correct hindfoot valgus with these procedures, it seems prudent to limit the indications to patients who have early disease accompanied by an isolated midfoot sag. In more advanced stage II disease, correction of deformity with a tendon transfer combined with a medial displacement calcaneal osteotomy or a lateral column lengthening is currently recommended. This allows for correction of deformity while sparing the hindfoot joints, which may be particularly important in young or active patients. Short-term studies showed excellent results, but long-term results are lacking. In stage III disease, in which the deformity is fixed, arthrodesis is the procedure of choice. Isolated talonavicular arthrodesis has been shown to correct nearly all aspects of the deformity with long-lasting results. This procedure results in nearly complete lack of hindfoot motion and may predispose the patient to adjacent joint arthrosis. In a patient who has stage III disease with arthrosis confined to the talonavicular joint, isolated talonavicular arthrodesis may be considered. This clinical situation is rare, and, in most patients, a triple arthrodesis is probably preferred. If residual deformity is present after these procedures, it must be addressed. Residual medial column instability may be addressed by adding a selective arthrodesis of the naviculo-cuneiform or first metatarsocuneiform joint, whereas residual forefoot varus or supination may be addressed with selected midfoot fusions with or without a cuneiform osteotomy.

Adolescent↗