David H Kim — Page 3 | Search PubMed

PubMedDate not supplied

Twisting and braiding reduces the tensile strength and stiffness of human hamstring tendon grafts used for anterior cruciate ligament reconstruction.

BACKGROUND: Twisting and braiding of four-strand hamstring tendon grafts used for anterior cruciate ligament reconstruction has been proposed, but not proven, as a method of improving tensile properties. HYPOTHESIS: Twisting and braiding four-strand human hamstring tendon grafts will have no significant effect on initial graft strength or stiffness. STUDY DESIGN: Paired in vitro biomechanical study. METHODS: In 12 matched cadaveric pairs, a doubled gracilis and semitendinosus tendon graft from one knee was twisted 180 degrees over a 30-mm length, while the doubled tendon graft from the contralateral knee was prepared for biomechanical testing with the graft strands in a parallel orientation. For an additional 12 matched pairs, a doubled graft was braided into a weave while the contralateral graft was prepared for testing in a parallel orientation. All four strands of each doubled tendon graft were equally tensioned with weights before being clamped in a tendon-freezing grip. Tensile testing was then performed. RESULTS: Twisting decreased graft strength by 26% (P < 0.01) and stiffness by 43% (P < 0.01), while braiding reduced strength by 46% (P < 0.01) and stiffness by 54% (P < 0.01), compared with parallel-oriented grafts. CONCLUSIONS: Equally tensioned, parallel four-strand human hamstring tendon grafts were significantly stronger and stiffer than twisted or braided four-strand hamstring tendon grafts. CLINICAL RELEVANCE: We caution against the use of twisted or braided four-strand hamstring tendon grafts for anterior cruciate ligament reconstruction.

Adult↗

PubMedDate not supplied

Shoulder injuries in golf.

Although often perceived as a leisurely activity, golf can be a demanding sport, which can result in injury, usually from overuse and sometimes from poor technique. The shoulder is a commonly affected site, with the lead shoulder, or the left shoulder in the right-handed golfer, particularly vulnerable to injury. A thorough understanding of the biomechanics of the golf swing is helpful in diagnosing and managing these injuries. Common shoulder problems affecting golfers include subacromial impingement, acromioclavicular arthrosis, rotator cuff tear, glenohumeral instability, and glenohumeral arthrosis. Although the majority of patients with these disorders will respond to nonsurgical treatment, including rest and a structured program of physical therapy, further benefits can be obtained with subtle modifications of the golf swing. Those golfers who fail to respond to nonsurgical management can often return to competitive play with appropriate surgical treatment.

Athletic Injuries↗