Short Crank Cycle Ergometry

Wed, 10 Sep 2008 00:00:00 EST

Robert E. Schwartz, Peter D. Asnis, John T. Cavanaugh, Stanley E. Asnis, John E. Simmons, Paul J. Lasinski
The change in knee angle during cycling was mathematically analyzed. It was determined that if the crank length of the cycle ergometer was shortened, the arc of knee motion necessary to cycle could be reduced. A computer program was written to represent the above mathematical model utilizing a patient's lower limb lengths to generate an individualized, range of motion profile. A custom cycle ergometer was built with interchangeable crank lengths of 80 mm, 110 mm, 140 mm, and 170 mm. This device can be adjusted to achieve a desired range of motion for a specific patient. The above custom cycle ergometer can be used on early postoperative knee patients who are unable to ride a conventional cycle ergometer because of a lack of knee motion or on patients who require a limited arc of motion in their postoperative therapy protocol.

J Orthop Sports Phys Ther 1991;13(2):95-100.

The Treatment of Articular Cartilage Defects Using the Microfracture Technique

Mon, 05 Feb 2007 09:45:00 EST

Thomas J. Gill, Peter D. Asnis, Capt Eric M. Berkson, Thomas J. Gill, Peter D. Asnis, Eric M. Berkson

Chondral defects of the articular surface pose a challenging problem to the orthopedic surgeon. The goal of surgery is to alleviate pain, maximize function, and prevent degenerative changes in the future. A number of techniques have been described to treat these lesions. When considering the treatment options for chondral defects, the surgeon must consider the size, depth, location, and chronicity of the lesion. In addition, the overall alignment of the joint must be evaluated.

Prior to treating chondral defects, it is important to understand the indications and contraindications for the microfracture technique. When indicated, the microfracture technique has many advantages over other surgical options. This technique is relatively easy to perform, cost effective, and has low patient morbidity. In addition, the microfracture technique does not burn any long-term bridges, enabling the surgeon to choose a different procedure to revise the chondral defect if the microfracture fails. It is important to understand the mechanism of healing by microfracture, including the effects of the local environment.

The postoperative protocol used after the procedure may be as important as the surgery itself. Understanding the science behind the microfracture procedure will lead to better surgical technique and improved outcomes.

J Orthop Sports Phys Ther. 2006; 36(10):728-738. doi:10.2519/jospt.2006.2444

Key Words: bone, knee, patellofemoral joint, tibiofemoral joint

Journal of Orthopaedic & Sports Physical Therapy - Peter D. Asnis, MD

Short Crank Cycle Ergometry

The Treatment of Articular Cartilage Defects Using the Microfracture Technique