Orthopaedic Bioengineering Laboratory

Dedicated to optimizing the evaluation, treatment, and rehabilitation of athletic injuries to the knee joint, the Bioengineering Laboratory at the Massachusetts General Hospital is one of most active and highly respected research laboratories in athletic medicine today.

Injuries to the knee often disturb the training and competition schedule of people involved in sports activities. In the healthy knee, the muscles surrounding the joint seamlessly work together with the cruciate and collateral ligaments, the menisci, and cartilage inside the joint to create a smooth, balanced knee motion. However, once one or more of the supporting structures is injured during sports, the remaining structures have to work harder in an attempt to stabilize the knee. Frequently, surgical and rehabilitation procedures are required to re-establish the balanced knee motion, and to prevent secondary injury to the other knee structures.

Under the direction of Dr. Guoan Li and Dr. Thomas Gill, the Bioengineering Laboratory research team has developed an advanced dual-orthogonal fluoroscopic and magnetic resonance imaging technique to quantify the in vivo biomechanics of the healthy, injured and surgically reconstructed musculoskeletal system. Current areas of study include:

The progress in understanding the injury mechanisms has established physiological guidelines for more accurate ligament reconstruction techniques and optimized rehabilitation protocols.

The Bioengineering Laboratory Sports Medicine Research Group consists of a team of biomechanical engineers, physicists, and physicians, working in close collaboration with the orthopaedic surgeons and physical therapists of the Massachusetts General Hospital Sports Medicine Service to help all patients achieve their maximum potential in sports.

More information on the Bioengineering Laboratory can be found at www.massgeneral.org/ortho/Bioengineering.htm

Recent Publications:

DeFrate LE, Sun H, Gill TJ, Rubash HE, Li G. In vivo tibiofemoral contact analysis using 3-D MRI-based knee models. J Biomechanics 2004;37:1499-1504.

Gill TJ, DeFrate L, Wang C, Carey CT, Zayontz S, Zarins B, Li G. The effect of posterior cruciate ligament reconstruction on patellofemoral contact pressures in the knee under simulated muscle loads. Am J Sports Med 2004;32:109-15.

DeFrate L, Ven A, Gill TJ, Li G. The effect of length on the structural properties of an Achilles tendon graft as used in posterior cruciate ligament reconstruction. Am J Sports Med 2004;32:993-7.

Park SE, Stamos BD, DeFrate LE, Gill TJ, Li G. The effect of posterior knee capsulotomy on posterior tibial translation during posterior cruciate ligament tibial inlay reconstruction. Am J Sports Med 2004;32:1514-9.

Li G, DeFrate L, Sun H, Gill TJ. In vivo elongation of the ACL and PCL during knee flexion. Am J Sports Med 2004;32:1415-9.

Li G, DeFrate LE, Zayontz S, Park SE, Gill TJ. The effect of tibiofemoral joint kinematics on patellofemoral contact pressures under simulated muscle loads. J Orthop Res 2004;22:801-6.

DeFrate LE, Gill TJ, Li G. In vivo function of the posterior cruciate ligament during weightbearing knee flexion. Am J Sports Med 2004;32:1923-8.

Li G, DeFrate LE, Park SE, Gill TJ, Rubash HE. In vivo articular cartilage contact kinematics of the knee: an investigation using dual orthogonal fluoroscopy and magnetic resonance image-based computer models. Am J Sports Med 2005;33:102-7.

Yoo JD, Papannagari R, Park S, DeFrate LD, Gill TJ, Li G. The effect of ACL reconstruction on knee joint kinematics under simulated muscle loads. Am J Sports Med 2005;33:240-6.

Li G, DeFrate L, Rubash HR, Gill TJ. In vivo kinematics of the ACL during weight bearing knee flexion. J Orthop Res 2005;23:340-4.

Li G, Park SE, DeFrate L, Schutzer ME, Ji L, Gill TJ, Rubash HE. The cartilage thickness distribution in the tibiofemoral joint and its correlation with cartilage-to-cartilage contact. Clin Biomech 2005;20:736-44.

Park SE, DeFrate L, Suggs J, Gill TJ, Rubash H, Li G. The changes in length of medial and lateral collateral ligaments during in-vivo knee flexion. Knee 2005;377-82.

Ramappa AJ, Apreleva M, Harrold FR, Fitzgibbons PG, Wilson DR, Gill TJ. The effects of medialization and anteromedialization of the tibial tubercle on patellofemoral mechanics and kinematics. Am J Sports Med 2006;34:749-56.

DeFrate LD, van der Ven A, Boyer PJ, Gill TJ, Li G. The measurement of the variation in the surface strains of Achilles tendon grafts using imaging techniques. J Biomechanics 2006;39:399-405.

Li G, Papannagari R, DeFrate L, Yoo JD, Park SE, Gill TJ. Comparison of the ACL and ACL graft forces before and after ACL reconstruction: an in-vitro robotic investigation. Acta Orthop Scand 2006;77:267-74.

DeFrate L, Papannagari R, Gill TJ, Li G. The six degrees-of-freedom kinematics of the knee after ACL deficiency: an in-vivo imaging analysis. Am J Sports Med 2006;34:1240-6.

Li G, Moses J, Pappanagari R, Pathare N, DeFrate L, Gill TJ. ACL-deficiency alters the in-vivo motion of the tibiofemoral contact points in both the anteroposterior and mediolateral directions. J Bone Joint Surg 2006;88:1826-34.

Papannagari R, Gill TJ, DeFrate LD, Moses J, Petruska AJ, Li G. In vivo kinematics of the knee after ACL reconstruction: a clinical and functional evaluation. Accepted for publication (Am J Sports Med).

DeFrate LD, Nha KW, Papannagari R, Moses J, Gill TJ, Li G. The biomechanical function of the patellar tendon during in vivo weight bearing flexion. Accepted for publication (J Biomech).

DeFrate LD, Gill TJ, Papannagari R, Jordan S, Nha K, Li G. The in-vivo kinematics of the anteromedial and posterolateral bundles of the anterior cruciate ligament during weight-bearing knee flexion. Accepted for publication (Am J Sports Med).

Pappanagari R, DeFrate LE, Nha KW, Moses JM, Moussa M, Gill TJ, Li G. The function of posterior cruciate ligament bundles during in-vivo knee flexion. Accepted for publication (Am J Sports Med).

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