STUDY DESIGN: Case report. BACKGROUND: Patellar fracture is a rare but significant complication following anterior cruciate ligament (ACL) reconstruction when using a bone-patellar tendon-bone (BPTB) autograft. The purpose of these case reports is to describe 2 cases in which patellar fracture occurred during rehabilitation after ACL reconstruction using a BPTB. CASE DESCRIPTION: Both patients were 23-year-old males referred for rehabilitation after ACL reconstruction using a BPTB autograft. They were both progressing satisfactorily in rehabilitation until sustaining a fracture of the patella. One fracture occurred during the performance of the eccentric phase of a knee extension exercise during the sixth week of rehabilitation (7 weeks postsurgery), whereas the other fracture occurred during testing of the patientís quadriceps maximum voluntary isometric contraction in the ninth week of rehabilitation (10 weeks postsurgery). Both patients were subsequently treated with open reduction and internal fixation of the patella. DISCUSSION: During rehabilitation following ACL reconstruction using BPTB autograft, clinicians should consider the need to balance the sometimes-competing goals of improving quadriceps strength while providing protection to the healing graft, minimization of patellofemoral pain, and protection of the patellar donor site. LEVEL OF EVIDENCE: Harm, level 4.

J Orthop Sports Phys Ther 2009;39(4):278-286, Epub 15 December 2008. doi:10.2519/jospt.2009.2864

KEY WORDS: ACL, failure, knee, load, strain

Ultrasound continues to be a popular modality among physical therapists and athletic trainers. Whether the intent of the ultrasound treatment is for thermal or nonthermal effects, it can be difficult to deliver an effective treatment over an irregular surface. Thermal ultrasound treatments are typically used to decrease muscle spasms, treat pain, increase circulation, and increase tissue extensibility. Draper and Prentice describe the “direct” technique of ultrasound as involving "actual contact between the applicator and the skin, with a thin film of couplant between." Although the direct technique has been recommended when therapeutic heating is desired, several authors discuss alternate, indirect techniques for performing thermal ultrasound treatments over irregular surfaces, thereby promoting a more uniform energy distribution during treatment. These indirect techniques have included water bath immersion, use of a commercial gel pad, and use of gel- or water-filled bladders. The effectiveness of water bath immersion as a method of delivering acoustic energy for purposes of tissue heating has, over the past years, yielded inconsistent results. Water has been found to be a good conductor, a poor conductor, and equivalent to other coupling agents when used to transmit ultrasound. Despite this conflicting evidence, authors continue to present the water bath technique as an appropriate indirect treatment alternative. It is our observation that clinicians continue to utilize this method in the athletic training room and physical therapy clinic. Research regarding the transmissivity of gel pads, bladder techniques, and water bath immersion are inconclusive and warrant investigation. The purpose of this in vitro study was to examine the relative transmissivity of a commercial gel pad, bladder techniques, and water bath immersion in the transmission of therapeutic ultrasound.

J Orthop Sports Phys Ther. 2000;30(5):263-269.

Key Words: thermal, nonthermal, water bath, gel pad, conductor