Deep digital flexor tenotomy as a treatment for chronic laminitis in horses: 35 cases (1988-1997)

OBJECTIVE: To determine long-term prognosis for horses with laminitis treated by deep digital flexor (DDF) tenotomy and to identify factors affecting success of the surgical procedure. DESIGN: Retrospective study. ANIMALS: 35 horses with laminitis treated by DDF tenotomy between 1988 and 1997. PROCEDURE: Information was obtained from individual medical records and follow-up telephone interviews with owners and referring veterinarians. Cumulative proportions of horses that survived 6 months and 2 years after tenotomy were determined. Effect of Obel grade of lameness on 6-month and 2-year survival and effect of distal phalangeal rotation on survival and future performance were evaluated by chi 2 analysis. Body weights of horses that survived > or = 2 years were compared with those of horses that survived < 2 years by ANOVA. RESULTS: 27 of the 35 (77%) horses survived > or = 6 months, and 19 of 32 (59%) survived > 2 years. Obel grade of lameness and body weight at time of surgery had no effect on 6-month or 2-year survival. Degree of distal phalangeal rotation had no effect on 2-year survival or the ability of horses to be used for light riding. Twenty-two of the 30 (73%) owners interviewed indicated they would have the procedure repeated on their horses given similar circumstances. CLINICAL IMPLICATIONS: DDF tenotomy is a viable alternative for horses with laminitis refractory to conventional medical treatment. In some instances, the procedure may be effective in returning horses to light athletic use.

Stable, low-loss optical waveguides and micromirrors fabricated in acrylate polymers.

Acrylate-based optical waveguides have been fabricated with optical loss of 0.5 dB/cm at 1300 nm by means of a new material system that ensures stable optical and mechanical properties over a wide temperature range. No increase in loss was measured after 500 h at temperatures up to 150 degrees C, and there was no significant increase in loss during short (<5 min) temperature excursions to 300 degrees C for bonding. Single-mode waveguides were fabricated with refractive indices for core and clad of 1.505 and 1.500, respectively, so that the mode field is very similar to that of single-mode silica fiber. Guides were fabricated on both planar and structured substrates of Si and GaAs as well as on substrates coated with metals and dielectrics. Fabrication involved spin coating and UV exposure to cross-link the polymer, but the substrate temperature did not exceed 180 degrees C. With this method guides could be fabricated on a range of substrates up to 125 cm in diameter, including those with multilayer metallization for multichip modules, providing optical interconnect capability. Microprism reflecting surfaces were fabricated in the waveguides to couple light out normal to the substrate. All the processing was compatible with normal semiconductor fabrication.

Racing-related factors and results of prerace physical inspection and their association with musculoskeletal injuries incurred in thoroughbreds during races.

OBJECTIVE: To describe and compare data from Thoroughbreds that sustained musculoskeletal injuries while racing with data from matched control horses. DESIGN: Matched case-control study. ANIMALS: 216 Thoroughbreds that sustained a musculoskeletal injury while racing and 532 horses from the same races that were not injured. PROCEDURE: Data regarding racing history, race-entrant characteristics, racing events determined by analysis of videotapes of races, and results of prerace physical inspections were determined for all horses. Injured horses were compared with control horses by using conditional logistic regression. RESULTS: Results of prerace inspection by regulatory veterinarians were significantly associated with injury. Odds of musculoskeletal injury, injury of the suspensory apparatus of the forelimb, and injury of the tendon of the superficial digital flexor muscle of the forelimb were 5.5 to 13.5 times greater among horses assessed to be at increased risk of injury by regulatory veterinarians on the basis of results of prerace inspection than for horses not considered to be at increased risk of injury. Odds of an abnormal finding in the suspensory ligament during prerace inspection were 3.4 times greater among horses that injured the suspensory apparatus than among control horses, and odds of an abnormal finding in the tendon of the superficial digital flexor muscle during prerace inspection were 15 times greater among horses that injured the tendon than among control horses. CLINICAL IMPLICATIONS: Regulatory veterinarians can identify horses during prerace physical inspection that have an increased risk of injury during races. Prerace physical inspections could be used to reduce the risk of injury to Thoroughbreds during races.

Case-control study of risk factors for the development of laminitis in the contralateral limb in Equidae with unilateral lameness.

OBJECTIVE: To identify risk factors associated with development of laminitis of the supporting limb in Equidae with unilateral laminitis and to determine the radiographic appearance of this type of laminitis. DESIGN: Retrospective analysis of medical records. ANIMALS: 20 Equidae with unilateral lameness that developed laminitis of the contralateral limb. PROCEDURE: Case animals were compared with matched and unmatched populations of control animals that did not develop contralateral limb laminitis. Lateromedial radiographic projections of affected feet were evaluated for evidence of laminitis. RESULTS: Body weight of case animals was not significantly different from that of control animals, but number of days that control animals were lame prior to recovery was significantly less than number of days that case animals were lame prior to the onset of laminitis. Lateromedial radiographic projections of the foot of the support limb were available for 16 of the 20 case animals. For all 16, thickness of the soft tissue dorsal to the distal phalanx was > 29% of the palmar cortical length of the distal phalanx, but only 1 had evidence of rotation of the distal phalanx. The proportion of case animals that were euthanatized was significantly greater than the proportion of control animals that were euthanatized. CLINICAL IMPLICATIONS: Duration of lameness, but not body weight, was a risk factor for development of laminitis in the contralateral limb in Equidae with unilateral lameness, and animals that developed this complication were more likely to be euthanatized than were animals that did not.

Social services to assist nutrition.

Social services to assist in improving nutritional status in older adults are reviewed. The social service interventions are placed in three broad categories of risk for older people to include poverty, social isolation, and dependency/disability. Each social service is identified and described to include eligibility and local resources. A social services intervention contact guide is provided as well as a state-by-stage aging services and resources directory.

Articular fracture of the dorsoproximolateral aspect of the third metatarsal bone in five standardbred racehorses.

Articular fracture of the dorsoproximolateral aspect of the third metatarsal bone (MT3) caused an acute onset of lameness in 5 horses; however, 3 of the horses had historical and radiographic or scintigraphic evidence of chronic tarsal and metatarsal disease before fracture. The pathogenesis of dorsoproximolateral fracture of MT3 remains unclear, but the fracture may occur as a result of the formation of abnormal bone in the proximal aspect of MT3. The prognosis for racing in horses with this fracture appears to be guarded.

Racing performance of standardbreds after conservative and surgical treatment for tarsocrural osteochondrosis.

A retrospective study of 114 Standardbred horses diagnosed with osteochondrosis (OC) of the cranial intermediate ridge of the distal tibia was carried out, and their subsequent race records were compared with 456 control horses. Each OC-affected horse was compared with 4 horses randomly selected from a list of horses matched to it by year of birth, sex and sire. The horses with OC were treated by arthroscopic removal of osteochondral fragments (N = 58) or managed conservatively (N = 56). The clinical presentation of these two groups was similar, although joint effusion was a more common presenting sign in the group that received surgical treatment. There was no association between presence of lameness and the type of treatment used. Data from the race records of treated and control horses (including the number of starts, lifetime earnings and record racing times) were compared. Overall, horses treated for OC had significantly fewer starts than, but earnings similar to, those in the control group. However, when stratification by sex was performed, females with OC made fewer starts and had lower earnings than did their control group. There was no significant difference in record time between OC-affected horses and controls. These results indicate that horses treated for osteochondrosis of the cranial intermediate ridge of the distal tibia performed as well as matched controls.

Relative incidence of dorsal metacarpal disease in young Thoroughbred racehorses training on two different surfaces.

The relative incidence of dorsal metacarpal disease was examined in two groups of Thoroughbred racehorses training on dissimilar surfaces (dirt and wood fibre). The horses and training methods appeared to be similar. The incidence of disease was significantly greater in the group training on dirt. There was no significant difference in the age distribution of incidence between the two groups and there was no association of incidence with sex or age within the training group. The number of fast miles worked by the two groups prior to the onset of dorsal metacarpal disease was lower in the group training on dirt.

Clinical examination of the equine foot.

The foot is the most common source of limb pain. The problems vary from simple to quite complex. An accurate diagnosis is dependent upon a thorough and detailed knowledge of anatomy and of what is available in the way of ancillary examination techniques. The correction of most foot problems requires an appreciation of a multitude of factors and a thorough knowledge of farrier science.

Do rates of intercellular adhesion measure the cell affinities reflected in cell-sorting and tissue-spreading configurations?

These experiments constitute the first experimental test of the hypothesis that the rates of adhesion between cells measure the intensities of adhesion or tissue affinities that could explain cell sorting and tissue spreading. For any set of relative adhesive intensities between cells in a heterogeneous population, a corresponding minimal free energy configuration can be calculated. This is the cell distribution toward which both cell sorting and tissue spreading should lead. Equilibrium configurations were determined for combinations of 7-day embryonic retina (R) with liver (L) and heart (H), both of which became completely enveloped by R. To produce these results, the adhesive intensities would have to fall in the sequences: L-L > L-R > R-R; and H-H > H-R > R-R. To determine whether the rates of adhesion fall into these same sequences, we have devised a new technique which measures the rates of adhesion between pairs of already-formed cell aggregates of like and unlike kinds. These fall in the sequence L-L > or = H-H > L-H > R-R > H-R > L-R. If these rates paralleled the corresponding intensities of adhesion at configurational equilibrium, both L and H should have become only partially enveloped by R. Thus the rates at which adhesions are initiated do not predict the relative adhesive intensities that could explain the observed tissue configurations.