Lateral Retinaculum Lengthening or Release Betina Bremer Hinckel, MD * , and Elizabeth A. Arendt, MD † Tightness of the lateral patellofemoral (PF) soft tissues is associated with many PF disorders, including lateral patellar compression syndrome, lateral patellar instability, and PF arthritis. Thus, it is an important component of many PF disorders. Although excessive lateral patellar tilt can be recognized on imaging, the contribution of lateral tightness must be verified by physical examination, that is, restraint to medial patellar displacement and lack of neutral patella tilt on physical examination. The indications for lateral release or lengthening for treating PF conditions begin with PF pain; diagnoses are made by physical examination and imaging. Taping and patellar unloading braces can be useful to simulate lateral patella unloading and thus may be predictive of outcome. Lateral lengthening is a more precise balance of the PF forces, and one can titrate more precisely the exact tissue that is being lengthened or released, reducing complication rates. Complications can include overrelease of the lateral structures leading to medial patella instability. Treatment options are closure of the lateral retinaculum, reconstruction of the lateral PF ligament, or lateral patellotibial ligament reconstruction. Oper Tech Sports Med 23:100-106 C 2015 Elsevier Inc. All rights reserved. KEYWORDS patellar dislocation, patellar instability, patellar tilt, surgery Introduction T ightness of the lateral patellofemoral (PF) soft tissues is associated with many PF disorders, including lateral patellar compression syndrome (LPCS), lateral patellar insta- bility, and PF arthritis. Thus, it is an important component of many PF disorders. LPCS was historically described as a functional lateralization of the patella created by increased lateral forces, decreased medial forces, or both, leading to cartilage wear and pain. 1,2 More recently, trochlear dysplasia has been recognized as a component of this syndrome. 3,4 The increased lateral tightness and dysplastic anatomy can result in cartilage wear and (potential) lateral PF arthritis, with pro- gressive joint space narrowing resulting in soft tissue contrac- tures and more lateral tightness. Lateral tightness has also been associated with PF instability. Along with medial ligamentous deficiency it can contribute to the imbalance of the medial and lateral forces predisposing to lateral patellar dislocation. 3-5 Limb alignment, in particular genu valgum and associated hypoplastic lateral femoral condyle, may be associated with a lateral patellar position throughout the range of motion, lateral procedures to reduce both bony and soft tissue overload may be required to clinically restore the knee to full function. Owing to the association of lateral patella soft tissue tightness with multiple PF disorders, and the ease of an arthroscopic lateral retinacular release (LRR), surgical correction of this tightness with a LLR or lengthening (LRR/L) has been used indiscriminately in the past. American Board of Orthopaedic Surgery statistics indicate that isolated LRR is among the more common procedures reported in case lists of candidates for the oral board examination. 6 However, in a survey of the members of the International Patellofemoral Study Group (IPSG), most respondents (89%) indicated that isolated LRR is a legitimate treatment, but used only on rare occasions (1%-2% of surgeries). 6 Inadequate surgical indications, ill-defined objective meas- ures including imaging and physical examination, and poor documentation of its surgical use and their outcomes have resulted in ambiguous guidelines for use of this surgical procedure. Potential complications are widespread, and 100 http://dx.doi.org/10.1053/j.otsm.2015.02.012 1060-1872//& 2015 Elsevier Inc. All rights reserved. *Institute of Orthopedics and Traumatology of the Clinical Hospital, Medical School, University of São Paulo, São Paulo, SP, Brazil. †Department of Orthopaedic Surgery, University of Minnesota, Minneapolis, MN. Address reprint requests to Elizabeth A. Arendt, MD, Deptartment of Orthopaedic Surgery, University of Minnesota, 2450 Riverside Ave, Suite R200, Minneapolis, MN 55454. E-mail: arend001@umn.edu