Publications by authors named "Michael A Tsai"
Unlabelled: We investigated talus and tibial plafond subchondral bone puncture strength based on surface location. Puncture tests of the subchondral bone were performed in 9 equal zones on the articular surface of 12 cadaver specimens aged 49.1 years (range, 36-56 years).
View Article and Find Full Text PDFWe compared the pullout strength of a suture-based anchor versus a bioabsorbable anchor in the distal fibula and calcaneus and evaluated the relationship between bone mineral density and peak load to failure. Eight paired cadaveric specimens underwent a modified Broström procedure and Achilles tendon reattachment. The fibula and calcaneus in the paired specimens received either a suture-based anchor or a bioabsorbable suture anchor.
View Article and Find Full Text PDFBackground: The authors' purpose was to determine if investigators can predict whether a needle is within a finger's flexor tendon by postinsertion tactile and visualization evaluation in an active range-of-motion cadaver model.
Methods: In 48 cadaver fingers, a 25-gauge needle, with a 1-cc syringe attached, was placed into one of three randomly assigned positions at the A2 pulley level: within the flexor digitorum profundus, within the flexor digitorum superficialis, or outside both flexors and the sheath. Each finger was cycled through full active range of motion as three hand surgeons, blinded to each other's responses and needle position, recorded whether they thought the needle was intratendinous.
Background: We hypothesized that transfer of the olecranon tip for simulated type III coronoid fracture would restore posterior ulnohumeral translation to a level not different from that in the intact state.
Methods: The collateral ligaments were left intact in 12 fresh-frozen cadaveric elbows, and all other soft tissues were removed. The entire coronoid process was osteotomized flush with the ventral aspect of the ulna and was reconstructed using the tip of the olecranon process.
Purpose: To compare stability and range of motion after hemi-hamate reconstruction versus volar plate arthroplasty in a biomechanical proximal interphalangeal (PIP) joint fracture-dislocation model.
Methods: Eighteen digits from 6 cadaver hands were tested. We created defects of 40%, 60%, and 80% in the palmar base of each digit's middle phalanx, simulating an acute PIP joint fracture-dislocation.
It is not known whether significant differences in the glenohumeral center of pressure and contact pressure exist between surface replacement arthroplasty and hemiarthroplasty compared with the native joint. Twelve fresh-frozen cadaveric shoulders were dissected free of soft tissue, and the joint capsule was removed. The scapula was potted with the glenoid parallel to the ground.
View Article and Find Full Text PDFPurpose: To test distal forearm stability after 3 surgical procedures for distal radioulnar joint (DRUJ) arthritis.
Methods: We tested 11 cadaver limbs with the DRUJ intact, after distal ulna-matched hemiresection, after Darrach distal ulna resection, and after unlinked total DRUJ arthroplasty. We evaluated distal forearm stability in neutral rotation, full pronation, and full supination in unweighted and 1-kg-weighted conditions.
Purpose: To determine the effect of lateral translation of the distal radius in the coronal plane on forearm rotation after distal radius fracture.
Methods: Ten fresh cadaveric limbs underwent distal radius osteotomy just proximal to the distal radial-ulnar joint to simulate an extra-articular distal radius fracture. We used an Agee Wrist Jack external fixator to create increasing magnitudes of distal fragment lateral translation in 2-mm increments.
Purpose: We performed a cadaveric biomechanical study to characterize proximal interphalangeal joint stability after an injury to different amounts of the volar articular base of the middle phalanx (intact, 20%, 40%, 60%, and 80% volar defects).
Methods: Eighteen digits on 6 hands were tested through full proximal interphalangeal joint range of motion using computer-controlled flexion and extension via the digital tendons. We collected proximal interphalangeal joint kinematic cine data in a true lateral projection with mini-fluoroscopy.