Comparison of radiographic and anatomic distal metatarsal articular angle in cadaver feet.

BACKGROUND: A few studies report correlations between radiographic and anatomic measurements of the distal metatarsal articular angle (DMAA). However, little is known about how the DMAA correlates with the hallux valgus angle (HVA) and with anatomic and clinical radiographic measurements. METHODS: We dissected, measured, and radiographed 39 cadaveric feet for evidence of hallux valgus and the DMAA. We then correlated these values with paired clinical radiographic measurements made by physician evaluators. RESULTS: Physician measurement of DMAA and anatomic measurement of DMAA were significantly correlated with a mean r = 0.64 (evaluator range, 0.44-0.66). Pairwise correlation between physician evaluators ranged from r = 0.63 to 0.84. Sixty-six percent of physician-measured DMAAs were within 5 degrees of anatomic DMAA. CONCLUSION: The percentage of radiographic DMAAs that were within 5 degrees of anatomic DMAAs was only 66%. Additionally, the DMAA was increased in the specimens with moderate and severe hallux valgus compared with those with normal or mild hallux valgus angles. CLINICAL RELEVANCE: The DMAA is an important consideration in patients with hallux valgus. While it is less reliable than other radiographic measures, it was correlated to deformity severity in specimen with hallux valgus.

First metatarsocuneiform joint mobility: radiographic, anatomic, and clinical characteristics of the articular surface.

BACKGROUND: The first metatarsocuneiform joint is involved in first ray biomechanics and related forefoot pathology. The purpose of this study was to evaluate the first metatarsocuneiform joint radiographic findings in relation to angular position of the radiographic beam, and to assess the joint mobility as it relates to the anatomic orientation of the facets on both radiographic imaging and gross anatomic dissection. METHODS: Thirty-nine cadaveric lower extremity limbs were stratified as normal, mild, moderate, or severe hallux valgus deformity. Mobility of the first metatarsocuneiform joint for each specimen was assessed using the Klaue device. The medial inclination angle (obliquity) of the first metatarsocuneiform joint was determined on both 10-degree and 20-degree anteroposterior radiographs. The lateral inclination angle of both the dorsal and plantar facets was determined on lateral radiographs. Each specimen was then dissected to directly inspect the metatarsocuneiform joint. RESULTS: The metatarsocuneiform joint mean height was 28.3 mm and the mean width was 13.1 mm. Twenty-three feet demonstrated a continuous cartilaginous surface, 15 feet demonstrated a bilobed cartilaginous surface, and 1 foot demonstrated completely separated facets. Dorsal facets were curved in 37 specimens and flat 2 specimens. Plantar facets were flat in 30 specimens and curved in 9 specimens. The medial inclination angle measured 15.8 degrees on the 10-degree radiograph and 2.6 degrees on the 20-degree radiograph. We were unable to establish any correlations of metatarsocuneiform joint angles or facet contour with mobility measured by the Klaue device. CONCLUSIONS: The metatarsocuneiform joint has a height to width ratio of nearly 2:1. Continuous and bilobed facets are both very common anatomic variants. The contour of the dorsal facet was predominantly curved and the contour of the plantar facet was predominantly flat. First metatarsocuneiform joint mobility does not appear to be dependent on the contour of the facets or the degree of medial inclination of the joint. CLINICAL RELEVANCE: Anatomic and radiographic findings with regard to mobility of the first metatarsocuneiform joint may assist the surgeon in interpreting the joint's relationship to hallux valgus deformity and to aid in clinical decision making. Our findings suggest that radiographic interpretation of medial inclination is unreliable and should not be used to determine the appropriateness of specific operative procedures.

Articular chondral damage of the first metatarsal head and sesamoids: analysis of cadaver hallux valgus.

BACKGROUND: Evidence of successful correction on postoperative hallux valgus imaging studies may not always correlate with patient satisfaction. Recent attention to the association of cartilaginous degeneration and hallux valgus may provide new insight into treatment algorithms and patient expectations. The purpose of this cadaveric study was to evaluate the degree of chondral damage as it relates to increasing hallux valgus deformity. METHODS: A total of 39 cadaver first metatarsophalangeal joints were evaluated by radiography, and then dissected to evaluate for chondral damage. Chondral lesion grade, size, and location were recorded and then analyzed based on patient demographics and hallux valgus angle. RESULTS: Twenty-nine of 39 specimens were considered to have hallux valgus characterized by a hallux valgus angle of 15 degrees or greater. Four of 39 (10%) specimens revealed absence of chondral lesions, and 3 of those were found in the group with a hallux valgus angle of less than 15 degrees. Chondral lesions of increasing size and grade were seen more commonly with a more severe hallux valgus deformity. Particular locations on the metatarsal head appeared to be more prone to cartilaginous lesions when compared to other locations. CONCLUSION: Assessment of first metatarsophalangeal joint articular damage with regard to hallux valgus may be an important clinical parameter for consideration. CLINICAL RELEVANCE: Operative intervention to realign the first metatarsophalangeal joint may correct malalignment and relieve pressure on the widened forefoot, but residual pain within the joint may emanate from preexisting articular cartilaginous lesions. These findings support the concept that earlier intervention with operative realignment of a hallux valgus deformity and specifically the sesamoid complex may diminish degenerative changes.

Metatarsophalangeal joint pathology in crossover second toe deformity: a cadaveric study.

BACKGROUND: Ligamentous and capsular insufficiency of the second metatarsophalangeal joint has been surgically treated for over two decades, mainly with indirect surgical repairs, which stabilize adjacent soft tissue and shorten or decompress the osseous structures. While ligamentous insufficiency has been described and recognized, degeneration of the plantar plate and tears of the capsule have rarely been documented. The purpose of this study was to document and describe the presence and pattern of plantar plate tears in specimens with crossover second toe deformities, and based on this, to develop an anatomical grading system to assist in the assessment and treatment of this condition. METHODS: Sixteen below-knee cadaveric specimens with a clinical diagnosis of a second crossover toe deformity were examined, and dissected by removing the metatarsal head. The pathologic findings of plantar plate and capsular pathology, as well as ligamentous disruption, were observed and recorded. Demographics of the specimens were recorded, and simulated weightbearing radiographs were obtained prior to dissection so that pertinent angular measurements could be obtained. RESULTS: Demographics demonstrated a high percentage of female specimens, and a typically older population that has been reported for this condition. Radiographic findings documented a high percentage of hallux valgus and hallux rigidus deformities. The MTP-2 and MTP-3 angles were divergent consistent with a crossover toe deformity. We consistently found transverse tears in the plantar plate region immediately proximal to the capsular insertion on the base of the proximal phalanx. With increasing deformity, wider distal transverse tears extending from lateral to medial were found. Midsubstance tears, collateral ligament tears, and complete disruption of the plantar plate were found in more severe deformities. CONCLUSION: In this largest series of cadaveric dissections of crossover second toe deformities, we describe the types and extent of plantar plate tears associated with increasing deformity of the second ray. We present, based on these findings, an anatomic grading system to describe the progressive anatomic changes in the plantar plate.

Fat embolism: evolution of histopathological changes in the rat lung.

The pathophysiology of Fat Embolism Syndrome (FES) is poorly understood and subject to some controversy. Evaluation of the evolution of histological changes in the lungs of patients with FES is impractical. The current theories of FES were established through acute clinical observations and acute animal experiments, but sequential changes in the histology of lungs over a prolonged period have not been made. The progressive effects of fat embolization of the lungs were examined in a rat model over a period of 11 days. Triolein, a major bone marrow fat, was administered to conscious Sprague-Dawley rats via the caudal vein. Rats were euthanized at 24, 48, 96 h, and 11 days, but some died within a few hours. Histomorphometric evaluations of lung tissue were made, including stains for fat, collagen, and smooth muscle actin. Arterial and arteriolar patency decreased progressively up to 96 h, but returned toward normal after 11 days. A striking finding was the very early presence of inflammation and fibrosis after only several hours, persisting up to 11 days. The results of this study provide evidence of both very early and prolonged changes due to fat embolization.