Patellofemoral pain

Patellofemoral pain is an extremely common disorder, especially in female athletes. There is, however, no true consensus as to the cause and appropriate treatment for patellofemoral pain. This article reviews the epidemiology of patellofemoral pain as well as the proposed etiologies, including quadriceps dysfunction, static alignment disorders, and dynamic alignment disorders. The article also reviews both conservative and surgical treatment of patellofemoral pain.     

Patellofemoral Malalignment

Abstract

This 27 year old male has had increasing bilateral medial knee pain over the last two years with the right knee being worse than the left. After a comprehensive physical therapy examination which included a motion analysis assessment, it was determined that the patient had bilateral patellofemoral malalignment. Customized orthotics which used both rearfoot and forefoot posting allowed this patient to resume his running program.     

Patellofemoral syndrome

This paper examines the condition of anterior knee pain known as patellofemoral pain syndrome. It describes the functional anatomy and biomechanics of the knee including normal movement, and factors which may destabilize the knee, and predispose it to injury. The controversial “Q” angle is discussed, as is its relationship to patellofemoral pain. The importance of balanced musculature to the integrity of the knee is emphasized as are the potential consequences of weak, or overly tight, muscles. Examination of the knee including patient history, standard orthopedic testing, observation of posture and gait, and palpation are summarized. Treatment protocols for the acute phase, recovery, and maintenance phases of treatment are described. These include gentle mobilization techniques, home exercises, and the occasional use of knee bracing and foot orthotics.     

Patellofemoral Cartilage Repair

Purpose of Review

This review provides an overview of well-established and newly developed cartilage repair techniques for cartilage defects in the patellofemoral joint (PFJ). An algorithm will be presented for approaching cartilage defects considering the distinct anatomy of both the patellar and trochlear articular surfaces.

Recent Findings

Recent studies on cartilage repair in the PFJ have demonstrated improved outcomes in an attempt to delay or obviate the need for arthroplasty, and improve symptoms in young patients. While autologous chondrocyte implantation shows good and excellent outcomes for chondral lesions, osteochondral defects are adequately addressed with osteochondral allograft transplantation. In case of patellar malalignment, concomitant tibial tubercle osteotomy can significantly improve outcomes. Particulated cartilage and bone marrow aspirate concentrate are potential new alternative treatments for cartilage repair, currently in early clinical studies.

Summary

Due to the frequency of concomitant anatomic abnormalities in the PFJ, a thorough clinical examination combined with careful indication for each procedure in each individual patient combined with meticulous surgical technique is central to achieve satisfying outcomes. Additional comparative studies of cartilage repair procedures, as well as investigation of newer techniques, are needed.

     

髌股关节排列紊乱的CT检查

目的　评价髌股关节排列紊乱的CT检查价值。方法　膝关节疼痛患者2 1例(2 6膝) ,对膝关节屈曲0°、15°、30°髌股关节进行CT检查,对髌骨的位置作出定性评价。结果　在伸展状态下至屈膝30°股肌收缩导致髌骨出现移位和倾斜。最常见的异常是髌骨移外侧位伴倾斜。在屈膝30°股肌收缩时,在患膝组中10个未发现髌股关节异常排列的膝中,有3例出现外移和/或倾斜。余下7个未发现髌股关节异常排列的膝中,在屈膝15°股肌收缩时,发现有3个为潜在性髌骨位置异常。结论　屈膝0°～30°在股肌收缩状态下,髌股关节CT扫描是检出髌股关节排列紊乱的有效手段。     

Treatment Options for Patellofemoral Arthritis

Purpose of ReviewTo present a synthesis of recent literature regarding the treatment of patellofemoral arthritisRecent FindingsRisk factors of PFJ OA include patella malalignment or maltracking, injury to supportive structures including the MPFL, dysfunction of hamstring and quadriceps coordination, lower limb alignment, trochlear dysplasia, patellar trauma, or ACL surgery. Special physical exam maneuvers include patellar grind test, apprehension test, and lateral patellar tilt angle. Radiographs that should be obtained first-line include weight bearing bilateral AP, lateral, and Merchant views. CT and MRI are used to assess trochlear dysplasia, excessive patellar height, and TT-TG distance. Non-operative management options discussed include non-pharmacologic treatment (patient education, self-management, physical therapy, weight loss), ESWT, cold therapy, taping, bracing, and orthotics. Pharmacologic management options discussed include NSAIDs, acetaminophen, oral narcotics, and duloxetine. Injection therapies include glucocorticoids, hyaluronic acid, PRP, and other regenerative therapies (BMAC, adipose, or mesenchymal stem cells). Other treatment options include radiofrequency ablation and botulinum toxin. The algorithm for the surgical treatment of PFJ OA can begin with arthroscopic assessment of the PF articular cartilage to address mechanical symptoms and to evaluate/treat lateral soft tissue with or without overhanging lateral osteophytes. If patients fail to have symptomatic improvement, a TTO can be considered in those patients less than 50 years of age or active patients >50 years old. In patients with severe PFJ OA, refractory to the above treatments, PFA should be considered. While early PFA design and technique were less than encouraging, more recent implant design and surgical technique have demonstrated robust results in the literature.SummaryPatellofemoral osteoarthritis is a challenging orthopedic problem to treat, in that it can often affect younger patients, with otherwise well-functioning knees. It is a unique entity compared to TF OA with distinct epidemiology, biomechanics and risk factors and treatment options.     

髌股关节对合关系的CT测量

目的 筛选诊断髌股关节对合异常的CT检查敏感参数.方法 对22例膝前痛患者42侧膝(症状组)及12例无症状者24侧膝(对照组)在屈膝0°、15°、30°、60°时分别对髌股关节行CT扫描,测量每个屈曲角度下的股骨滑车角、外侧髌股角、髌骨倾斜角、和谐角、髌股指数.结果 症状组髌股关节的和谐角、髌股指数明显大于对照组(P<0.01),其余参数无显著性差异(P>0.05).结论 CT扫描是检出髌股关节异常对合的有效方法,其中和谐角、髌股指数对评价髌股关节异常对合更为敏感.     

Individualized Physiotherapy in the Treatment of Patellofemoral Pain

Background and Purpose. Patellofemoral pain (PFP) is associated with a wide range of local and global physical factors possibly contributing to pain and thus requires detailed assessment and individualized treatment. Yet, no cohort study was found that assessed the value of individualized physiotherapy, probably because this approach lends itself to clinical practice but not to scientific research. Most studies focus on a ‘knee’ or ‘hip’ treatment approach irrespective of individual global differences in lower limb alignment, movement patterns and muscle tightness. Therefore, this study aimed to determine the effectiveness of supplementing local treatment of PFP with individualized treatment targeting global contributing factors. Secondarily it aimed to subgroup the patients according to variations in lower limb alignment/laxity, movement patterns, biarticular muscle tightness and joint degeneration. Method. Forty‐one patients (60 knees) with PFP who had followed a programme of local quadriceps strengthening, quadriceps stretching and taping for one fortnight were prescribed an individualized programme based on assessment. This global assessment included lower limb postural alignment, movement patterns, muscle tightness and range of motion. Another fortnights treatment was prescribed accordingly and included specific, individualized postural and movement retraining, stretching and functional weight‐bearing, strengthening exercises. Seven outcome measures, namely four pain measures, isokinetic quadriceps strength, quadriceps length and eccentric knee control, assessed improvement. Results. All outcome measures showed further significant improvement following individualized treatment (p < 0.03). Patients fell into four broad physical subgroups: hypermobility (often with malalignment), hypomobility (with three of four tight muscle groups), faulty movement patterns (mostly dynamic knee valgus) and patellofemoral osteoarthritis. Conclusions . Individualized treatment supplementing local standard physiotherapy for PFP leads to further significant improvement over 2 weeks. This study highlights the importance of assessing patients globally in order to optimize treatment and ongoing improvement. Recognition of different subgroups may guide treatment that should include both local and deficit‐targeted global treatment. Copyright © 2014 John Wiley & Sons, Ltd.     

Patellofemoral joint forces during ergometric cycling

We estimated the patellofemoral joint forces generated during pedaling on a bicycle ergometer. Our calculations were based on measurements from a force transducer mounted on the pedal, 16-mm cine-film sequences, and biomechanical models of the cycling motion and of the patellofemoral joint. Six healthy male subjects cycled at different work loads, pedaling rates, saddle heights, and pedal foot positions. The maximum patellofemoral compressive force was 905 N (1.3 times body weight [BW]) when cycling with an anterior foot position at 120 W, 60 rpm, and middle saddle height. The mean peak compressive force between the quadriceps tendon and the intercondylar groove was 295 N (0.4 BW), and the patellar-tendon and quadriceps-tendon strain forces were 661 N (0.9 BW) and 938 N (1.3 BW), respectively. The patellofemoral joint forces were increased with increased work load or decreased saddle height. Different pedaling rates or foot positions did not significantly change these forces.     

Acute Patellofemoral Dislocation: Controversial Decision-Making

Purpose of ReviewThe topic of acute patella dislocations is controversial. Discussions revolve around which individuals need early surgery, identification of risk factors, and rehabilitation protocol. The purpose of this review is to discuss the current recommendations for non-operative and/or operative management of first-time dislocators.Recent FindingsRecent studies have made it clear that not all patellar dislocations are the same, not all patients do well with conservative treatment, and risk stratification can identify individuals at high risk of recurrence who would benefit from early surgical intervention. Risk factors that have been identified include younger age, skeletally immature, contralateral instability, trochlear dysplasia, patella alta, increased tibial tubercle-trochlear groove distance, and increased patella tilt. The PAPI (Pediatric and Adolescent Patellar Instability) RCT study and JUPITER (Justifying Patellar Instability Treatment by Early Results) prospective cohort study have been carefully developed, are under way, and will provide further guidance.SummaryIn summary, the management of acute patellar dislocations is evolving. Surgery for patients with osteochondral loose bodies should include fixation as well as soft tissue stabilization. The standard of care for patients with an acute patellar dislocation without osteochondral loose bodies or fracture is non-operative treatment. However, imaging for all first-time dislocators is indicated to stratify risks and determine risk profile. If an individual is at high risk, soft tissue stabilization may be considered. Still, most patients will be treated non-operatively.     

Patellofemoral pain and asymmetrical hip rotation

BACKGROUND AND PURPOSE: Patellofemoral joint problems are the most common overuse injury of the lower extremity, and altered femoral or hip rotation may play a role in patellofemoral pain. The purpose of this case report is to describe the evaluation of and intervention for a patient with asymmetrical hip rotation and patellofemoral pain. CASE DESCRIPTION: The patient was a 15-year-old girl with an 8-month history of anterior right knee pain, without known trauma or injury. Prior to intervention, her score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was 24%. Right hip medial (internal) rotation was less than left hip medial rotation, and manual muscle testing showed weakness of the right hip internal rotator and abductor muscles. The intervention was aimed at increasing right hip medial rotation, improving right hip muscle strength (eg, the muscle force exerted by a muscle or a group of muscles to overcome a resistance), and eliminating anterior right knee pain. OUTCOMES: After 6 visits (14 days), passive left and right hip medial rotations were symmetrical, and her right hip internal rotator and abductor muscle grades were Good plus. Her WOMAC score was 0%. DISCUSSION: The patient had right patellofemoral pain and an uncommon pattern of asymmetrical hip rotation, with diminished hip medial rotation and excessive hip lateral (external) rotation on the right side. The patient's outcomes suggest that femoral or hip joint asymmetry may be related to patellofemoral joint pain.     

急性滑脱性髌股关节撞击症的治疗观察

目的：进一步了解急性滑脱性髌股关节撞击症,探讨其发生机制,诊断及治疗。方法：我院2004-07-2006-03共收治了7例急性膝关节扭伤患者,均为不慎滑倒损伤,膝关节迅速肿胀,疼痛剧烈,不能曲伸。X线片未见异常或者髌骨上下极见少许模糊影,M R I示髌骨内侧面骨软骨骨折行急诊切开减压,骨折复位内固定,术后外固定3周,开始膝关节主动功能锻炼,5-6周CT显示骨折块在位,内固定钢丝在位,股骨髁软骨下骨挫伤。结果：均获随访12-28个月,平均20个月,未出现髌股关节疼痛,髌骨内侧面骨软骨骨折块无脱落。结论：急性滑脱性髌股关节撞击症患者,应早期诊断,急诊手术治疗,术后1周行主动股四头肌收缩训练,术后3周去除外固定主动膝关节功能锻炼,可收良好的疗效。     

Future Directions in Patellofemoral Imaging and 3D Modeling

Purpose of ReviewPatellofemoral instability involves complex, three-dimensional pathological anatomy. However, current clinical evaluation and diagnosis relies on attempting to capture the pathology through numerous two-dimensional measurements. This current review focuses on recent advancements in patellofemoral imaging and three-dimensional modeling.Recent FindingsSeveral studies have demonstrated the utility of dynamic imaging modalities. Specifically, radiographic patellar tracking correlates with symptomatic instability, and quadriceps activation and weightbearing alter patellar kinematics. Further advancements include the study of three-dimensional models. Automation of commonly utilized measurements such as tibial tubercle–trochlear groove (TT-TG) distance has the potential to resolve issues with inter-rater reliability and fluctuation with knee flexion or tibial rotation. Future directions include development of robust computational models (e.g., finite element analysis) capable of incorporating patient-specific data for surgical planning purposes.SummaryWhile several studies have utilized novel dynamic imaging and modeling techniques to enhance our understanding of patellofemoral joint mechanics, these methods have yet to find a definitive clinical utility. Further investigation is required to develop practical implementation into clinical workflow.     

Patellofemoral joint kinetics during squatting in collegiate women athletes

OBJECTIVE:To characterize the biomechanics of the patellofemoral joint during squatting in collegiate women athletes. DESIGN: Repeated measures experimental design. BACKGROUND: Although squatting exercises are required components of most intercollegiate resistance-training programs and are commonly performed during rehabilitation, the effects of various squatting depths on patellofemoral joint stress have not been quantified. METHODS: Anthropometric data, three-dimensional knee kinematics, and ground reaction forces were used to calculate the knee extensor moment (inverse dynamics approach) in five intercollegiate female athletes during squatting exercise at three different depths (approximately 70 degrees, 90 degrees and 110 degrees of knee flexion). A biomechanical model of the patellofemoral joint was used to quantify the patellofemoral joint reaction force and patellofemoral joint stress during each trial. RESULTS: Peak knee extensor moment, patellofemoral joint reaction force and patellofemoral joint stress did not vary significantly between the three squatting trials. CONCLUSIONS: Squatting from 70 degrees to 110 degrees of knee flexion had little effect on patellofemoral joint kinetics. The relative constancy of the patellofemoral joint reaction force and joint stress appeared to be related to a consistent knee extensor moment produced across the three squatting depths. RELEVANCE: The results of this study do not support the premise that squatting to 110 degrees places greater stress on the patellofemoral joint than squatting to 70 degrees. These findings may have implications with respect to the safe design of athletic training regimens and rehabilitation programs.     

Patellofemoral pain syndrome: evaluation and treatment

Patellofemoral pain syndrome is common among athletes and non-athletes. It results from an imbalance of forces acting on the patellofemoral joint, which leads to increased strain on the peripatellar soft tissues, increased patellofemoral joint stress, or both. The most important risk factors are overuse, quadriceps weakness, and soft-tissue tightness. In most cases, the etiology is multifactorial. A careful history and targeted physical examination will confirm the diagnosis and determine the most appropriate treatment. A physical therapy program that employs quadriceps strengthening, manual stretching of the lateral patellar soft-tissue structures, patellar taping, and biofeedback is successful in the majority of cases. Surgery maybe required for the few patients who do not respond to nonoperative management.