See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/252325604 Surgical Treatment of a Chronically Fixed Lateral Patella Dislocation in an Adolescent Patient Article in Orthopedic Reviews · June 2013 DOI: 10.4081/or.2013.e9 · Source: PubMed CITATIONS READS 5 159 6 authors, including: Xinning Li Boston University 104 PUBLICATIONS 867 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Commentary & Perspective Total Hip Arthroplasty View project All content following this page was uploaded by Xinning Li on 03 June 2014. The user has requested enhancement of the downloaded file. Orthopedic Reviews 2013; volume 5:e9 Surgical treatment Introduction Correspondence: Xinning Li, Hospital for Special of a chronically fixed lateral Surgery, Department of Orthopedic Surgery, patella dislocation Acute patellar dislocation or subluxation is a Division of Sports Medicine, New York, NY 10021, common cause for knee injuries in the United USA. in an adolescent patient E-mail: [email protected] States and accounts for 2% to 3% of all injuries.1 Xinning Li,1 Natalie M. Nielsen,2 Up to 49% of patients will have recurrent sublux- Key words: pediatric orthopedics, patella disloca- ations or dislocations.2-4 Importance of both soft Hanbing Zhou,2 Beth Shubin Stein,1 tion, Faulkerson procedure, MPFL reconstruction. tissue [predominantly, the medial Yvonne A. Shelton,2 Brian D. Busconi2 patellofemoral ligament (MPFL), which is Contributions: XL contributed to the conception, 1Department of Orthopaedic Surgery, responsible for 60% of the resistance to lateral drafting, revision, and collection of the patient Division of Sports Medicine and Shoulder dislocation] and bony constraint of femoral data and radiographs of this study. NE and HZ contributed to the drafting and revision of this and Elbow Surgery, Boston University trochlea in preventing subluxation and disloca- manuscript. BSS, YS and BB contributed to the 5,6 School of Medicine, Boston, MA; tion is well documented. Reconstruction of the critical reviewing and editing of this manuscript. 2Department of Orthopedic Surgery, MPFL has been proven clinically to provide func- University of Massachusetts Medical tional improvement in patients with recurrent Conflict of interests: the authors declare no Center, Worcester, MA; 3Department of patellar instability without significant increase potential conflict of interests. in Q-angle or tibial tubercle-trochlea groove (TT- Orthopedic Surgery, Division of Sports TG) distance.7,8 In the subset of patients with Funding: funding was provided internally by the Medicine, Hospital for Special Surgery, chondral changes (localized to the lateral and University of Massachusetts Medical Center - division of Sports Medicine. New York, NY, USA inferior patella) and a lateralized tibial tubercle (TT-TG >20 mm), an anteromedial tibial tuber- Received for publication: 10 March 2013. cle transfer has been shown to provide good to Revision received: 29 March 2013. excellent patellofemoral pain relief as well as Accepted for publication: 21 April 2013. Abstract treating the instability as it modifies both the Q- angle while unloading the patellofemoral joint onlyThis work is licensed under a Creative Commons stress.9 Utilizing either a soft tissue and/or bone- Attribution NonCommercial 3.0 License (CC BY- Acute patellar dislocation or subluxation is a NC 3.0). common cause for knee injuries in the United based procedure can be successful in the treat- ment of patients with recurrent patella instabili- States and accounts for 2% to 3% of all injuries. use ©Copyright X. Li et al., 2013 Up to 49% of patients will have recurrent sublux- ty. However, the treatment of older patients with Licensee PAGEPress, Italy ations or dislocations. Importance of both soft a fixed lateral patella dislocation can be chal- Orthopedic Reviews 2013; 5:e9 tissue (predominantly, the medial lenging. Most patients are surgically treated in a doi:10.4081/or.2013.e9 patellofemoral ligament, MPFL, which is respon- timely manner with appropriate conservative or sible for 60% of the resistance to lateral disloca- surgical management to maximize their overall tion) and bony constraint of femoral trochlea in function. We present a rare case of an adoles- cent male (15 years old) with a history of trau- anterolateral aspect of the knee (Figure 1). preventing subluxation and dislocation is well matic lateral patella dislocation during child- There was minimal pain with palpation of the documented. Acute patella dislocation will hood and required delayed surgical reconstruc- patella. Knee range of motion was limited to 15° require closed reduction and management typi- tion. The patient and parents were informed that to 120° with no pain at the extremes of motion cally consist of conservative or surgical treat- the data concerning his case would be submitted and stable to provocative testing. Examination of ment depending on the symptoms and recur- for publication, and both has provided us with the contra-lateral knee was normal. An attempt rence of instability. Most patients are diagnosed consent. to reduce the patella in clinic was unsuccessful and treated in a timely manner. We present a 15 as there was minimal patellar movement with years old male with a missed traumatic lateral medially directed force. Initial radiographs of the patella dislocation during childhood. The patient knee (Figure 2) demonstrated a lateral dislocat- presented as an adolescent with a chronically Case Report ed patella with no fracture or patella alta and no fixed lateral patella dislocation andNon-commercial was manage- trochlear dysplasia (no crossing sign). Magnetic ment with surgery. The key steps in the surgical A 15-year-old active male referred to our resonance imaging (MRI) of the right knee con- reconstruction of this patient required first orthopedic clinic after an unsuccessful attempt firms the lateral patella dislocation with attenu- mobilizing the patella with a lateral retinacular at a closed reduction of a right lateral patellar ation of the MPFL, mild joint effusion, and with- release and V-Y lengthening of the shortened or dislocation in the emergency room. The patient out bone edema (Figure 3). TT-TG distance was contracted quadriceps tendon. Then a combina- states that he sustained a knee injury by falling 33 mm on computed tomography (CT) scan. tion of MPFL reconstruction using the semi- off a fire hydrant. He also reports a vague histo- Both the conservative and surgical options was tendinosis autograft, tibial tubercle osteotomy ry of trauma to this knee during his childhood discussed with the patient and his family, deci- with anterio-medialization, and lateral facetec- but with no previous surgical interventions. The sion was made to proceed with surgical inter- tomy was performed. At the one-year follow-up, patient was seen by a physician in Puerto Rico vention. our patient had improved knee range of motion over ten years ago for this injury, but both he and Anterior incision and a medial para-patellar and decrease in pain. Chronically fixed lateral his parents was not sure of the diagnosis. arthrotomy were performed. There was signif- dislocated patella is a rare and complex problem Further questioning reveals that the patient and icant lateral displacement of the tibial tubercle to manage in older patients that will require a his parents always noticed a bump on the lateral with a fixed patella in the lateral gutter. Due to thorough work-up and appropriate surgical plan- aspect of his right knee since childhood with the contracture of the vastus lateralis region, ning along with reconstruction. limitation of motion and activity. Gait is slightly we first proceeded with a lateral retinacular antalgic and initial examination of this patient’s release and V-Y lengthening of quadriceps ten- right knee reveals a gross deformity on the don was needed to fully mobilize the patella for [Orthopedic Reviews 2013; 5:e9] [page 45] Case Report reduction (Figure 4). The articular surface of more than 10 years from the original event as degeneration/malformation was seen at the the patella was then evaluated and a signifi- an adolescent (15 years old). Both the patient lateral facet. Thus, we performed a lateral face- cant degenerative lateral facet was noted. As a and his parents report noticing a deformity or tectomy to remove the osteophytes and malfor- result, we performed a lateral facetectomy of bump on his knees since the original injury. A mation. After the patella was centered on the the patella to improve its articulation with the physician in Puerto Rico saw him but no treat- groove, an anteromedialization of the tibial trochlea. Next, a tibial tubercle osteotomy to ment was performed. Given the chronicity of tubercle was performed to decrease the Q- anteromedialized the tubercle was performed the lateral dislocation and the soft tissue con- angle and improve tracking. Given the attenu- to both centralize and decrease the loading tracture, the first step in our operative man- ated proximal tissue, we also reconstructed the stress on the patella. Semitendinosis autograft agement was to release the patella from the MPFL with a semitendinosis autograft to pro- was then harvested to reconstruct the MPFL at lateral gutter. Lateral release was performed vide a checkrein to lateral patella subluxation. its isometric point. The graft on the patella was first, however, the quadriceps tendon was also Tensioning of the graft was done after the tunneled and sutured onto itself while the contracted and the patella was unable to be tubercle osteotomy with the knee in 30 degrees femur fixation was performed with a tenodesis reduced. Thus, we performed a V-Y lengthen- of flexion in order to engage the patella in the screw. At this point, we were able to achieve ing of the quadriceps tendon. Once the patella trochlea and prevent over tightening of the full extension and 125 degree of flexion. was mobilized, the next step was to evaluate MPFL.