Graphics-based simulations can provide insight into the functional consequences of surgery and serve as the basis for surgical design. We have developed simulations to study the biomechanical consequences of a variety of surgeries, several of which are listed below.

	Muscle-Tendon Lengthenings, procedures in which the tendon and/or aponeurosis of a muscle is lengthened in muscles that are thought to be short and restrict movement. Our simulations have identified the relationship between tendon lengthening strategies and post-operative function.
	Tendon Transfers, procedures in which the tendon of a muscle is detached from its insertion and re-attached to a new location to augment function in persons with cerebral palsy or spinal cord injury. Our simulations have provided insight the relationship between transfer approach and post-operative strength and range of motion.
	Osteotomies, procedures in which the bones are divided and re-aligned to restore more normal limb function. Our simulations have provided insight into the effects of bone re-alignment strategies on muscle lengths and moment arms.
	Total Knee Replacements are performed in patients with degenerative joint disease. Our simulations have revealed the relationships between implant design, surgical technique, and knee motion and stability.
	Total Hip Replacements. Our simulations have provided insight into the relationship betwen implant placement and hip muscle strength.

Associated Publications

Saul, Murray, Hentz, and Delp. "Biomechanics of the Steindler Flexorplasty Surgery: A Computer Simulation Study." Journal of Hand Surgery, 2003. (Download PDF file)

Schmidt, Arnold, Carroll, Delp. "Length Changes of the Hamstrings and Adductors Resulting from Derotational Osteotomies of the Femur." Journal of Orthopaedic Research, 1999. (Download PDF)

Herrmann and Delp. "Moment Arms and Force-Generating Capacity of the Extensor Carpi Ulnaris After Transfer to the Extensor Carpi Radialis Brevis."Journal of Hand Surgery, 1999. (Download PDF)

Delp, Stulberg, Davies, Picard, Leitner. Computer Assisted Knee Replacement, Clinical Orthopaedics and Related Research, 1998. (Download PDF)

Piazza and Delp. "Three-dimensional Dynamic Simulation of Total Knee Replacement Motion During a Stepup Task." ASME Journal of Biomechanical Engineering, 2001. (Download PDF)

Piazza, Delp, Stulberg, Stern. "Posterior tilting of the tibial component decreases femoral rollback in posterior-substituting knee replacement."Journal or Orthopaedic Research, 1998. (Download PDF)

Free and Delp. "Effects of Trochanteric Transfer on the Moment Arms, Lengths, and Force-Generating Capacities of the Hip Abductors." Journal of Orthopaedic Research, 1996. (Download PDF)

Delp, Wixson, Kocmond, Komattu. "How superior placement of the joint center in total hip arthroplasty affects the abductor muscles." Clinical Orthopaedics and Related Research, 1996. (Download PDF)

Kocmond, Delp, Stern. "Stability and range of motion of Insall-Burstein condylar prostheses: a computer simulation study."Journal of Arthroplasty, 1995. (Download PDF)

Delp, Kocmond, and Stern. "Trade-offs between motion and stability in posterior substituting knee arthroplasty design."Journal of Biomechanics, 1995. (Download PDF)

Delp, Statler, Carroll. "Preserving plantarflexion strength after surgical treatment for contracture of the triceps surae: a computer simulation study."Journal of Orthopaedic Research, 1995. (Download PDF)

Delp, Ringwelski, Carroll. "Transfer of the rectus femoris: effects of transfer site on moment arms about the knee and hip."Journal of Biomechanics, 1994. (Download PDF)

Delp, Komattu, Wixson. "Superior displacement of the hip in total joint replacement: effects of prosthetic neck length, neck-stem angle, and anteversion angle on the moment-generating capacity of the muscles." Journal of Orthopaedic Research, 1994. (Download PDF)

Delp and Zajac. "Force- and moment-generating capacity of lower-limb muscles before and after tendon lengthening." Clinical Orthopaedics and Related Research, 1992. (Download PDF)

Vasavada, Delp, Maloney, Schurman, Zajac. "Compensating for changes in muscle length in total hip arthroplasty: effects on the moment-generating capacity of the muscles." Clinical Orthopaedics and Related Research, 1994. (Download PDF)

Delp, Bleck, Zajac, Bollini. "Biomechanical analysis of the Chiari pelvic osteotomy: preserving hip abductor strength." Clinical Orthopaedics and Related Research, 1990. (Download PDF)