Hip Strengthening Versus Quadriceps Based Training for Patellofemoral Pain Syndrome

Does Isolated Hip Strengthening for Patellofemoral Pain Syndrome Give Better Long Term Results Than Traditional Quadriceps Based Training? A Randomised Controlled Trial.

This is a Randomized Controlled Trial (RCT) regarding conservative treatment of Patellofemoral Pain Syndrome (PFPS). Patellofemoral Pain Syndrome (PFPS) is a very common cause of knee pain in young active adults with a high rate of recurrent and/or chronic occurrence. PFPS is notoriously difficult to treat and has been referred to as "one of the most vexatious clinical challenges in rehabilitative medicine". Its etiology is unclear but is commonly thought to be related to pathomechanics in the patellofemoral joint (PFJ). There are many factors that can influence PFJ mechanics. Among these, quadriceps strength and timing has been shown to be important. As such, treatment of PFPS has traditionally been based on correction of pathomechanics through influencing quadriceps strength and timing. However, a growing body of evidence is revealing the importance of strength and control of hip abduction and external rotation in PFPS. Hip strength in ab/adduction and rotation is thought to influence femoral positioning in the patellofemoral joint, thereby affecting PFJ mechanics. Several cohort and smaller RCT studies within the last 7 years have shown that additional exercises for hip strength and control give an improved effect in pain and function compared with quadriceps based training alone. A smaller RCT from 2012 compared isolated hip strengthening exercises to a control group and found surprisingly good results on pain in function in the hip strengthening group. The investigators plan a RCT in which isolated hip strengthening will be compared to traditional quadriceps training and a control group which will receive no structured training. Primary outcomes will be pain and function. This high-quality study will include 40-50 patients in each group, making it one of the largest of its kind on conservative treatment for PFPS. In contrast to the vast majority of studies of this type, this study will also include men, which will potentially help to fill a significant gap in the literature on this subject. The investigators study will therefore be an important contribution to elucidating the etiology of PFPS and improving treatment options for both men and women in the future. As well, the role of psychometric parameters will be examined and a standardized clinical test for hip abduction endurance will be developed. Follow-up at 3 months and 12 months is completed and published. A 5-year follow-up of the same patients is underway.

Patellofemoral pain syndrome, Anterior knee pain, Randomised controlled trial, Exercise intervention, Hip strengthening, Quadriceps based training, Anterior knee pain score

Patients receive standardised information concerning patellofemoral pain syndrome, but receive no prescribed exercise regime. They are encouraged to remain active.

Exercise program that is carried out by subjects under supervision once a week and then performed at home 2 additional times without supervision for a total of 6 weeks. Hip strengthening group will train hip abduction, hip external rotation and hip extension.

Exercise program that is carried out by subjects under supervision once a week and then performed at home 2 additional times without supervision for a total of 6 weeks. Quadriceps group will train mini-squat, straight leg raising, terminal extensions.

Patients receive standardised information concerning patellofemoral pain syndrome, but receive no prescribed exercise regime. They are encouraged to remain active.

Anterior Knee Pain Score (AKPS) is a measurement of subjective symptoms and functional limitations in patellofemoral pain, and has been validated for use in this patient population. The AKPS consists of a 13-point questionnaire with categories related to different levels of function in the knee. The categories within each question are weighted, and the responses are summed for an overall index where 100 represents perfect function. The mean clinically important difference (MCID) has been determined to be 10 points. This questionnaire will be translated to Norwegian and validated according to standard scientific procedures with approval from Kuala et al.

An 18-point likert scale for measuring patients' global assessment of change compared with baseline will be carried out at 3 and 12 months. The scale ranges from -9 (maximum deterioration) to +9 (maximum improvement).

The step down as performed according to standardised instruction will be used to quantify changes in patients' function. The measure is number of repetitions in 30 seconds.

Testing is carried out in side-lying position with a 5kg weight around the ankle of the upper leg, which is abducted to 30 degrees above the horizontal plane. Time successfully held in target area is measured in seconds.

EQ-5D-5L is calculated on the basis of five questions about daily activities, pain and psychological status with five possible answers for each question. In addition the subject scores his/her overall health on a 1-100 scale. The results are translated to a single summary index value through the use of a table

The Tampa scale for kinesiophobia (TSK) is a 13 -item questionnaire aimed at the assessment of fear of movement/re-injury. Each item is scored on a 4-point Likert scale with alternatives ranging from "strongly disagree" (0) to "strongly agree". This gives a possible total score range from 0 to 52.

The Hopkins Symptom Checklist (HSCL) is a symptom inventory which measures symptoms of anxiety and depression.

K-SES is a self-administered instrument consisting of in total four sections in which patients score how certain they are about specific activities currently and in the future.

An adaptation of the Standardised Nordic Questionnaire will be used to register the number of painful areas.

Inclusion Criteria: Age 16-40 years Insidious onset of symptoms not related to trauma Symptoms more than 3 months A minimum of VAS 3 on VAS-W Peri- or retropatellar pain during or after at least two of the following: Stair ascent or descent, hopping, running, prolonged sitting, squatting, kneeling. Pain on one of the following: Compression of the patella, palpation of the patellar facets Exclusion Criteria: Clinical findings indicative of meniscal or other intraarticular injury Clinical findings indicative of injury to or increased laxity of cruciate or collateral ligaments Findings on MRI indicative of other intraarticular pathology. Clinical and/or x-ray findings (plain anterior-posterior, lateral and skyline view) indicative of osteoarthritis, Osgood-Schlatter or Sinding-Larsen-Johanssen syndrome Clinical findings indicative of knee joint effusion Significant pain from hip or lumbar spine on clinical evaluation, with potential for causing referred pain to the knee or hindering the patient's ability to perform the prescribed exercises. Recurrent patellar subluxation or dislocation. Previous surgery to the knee joint NSAID or cortisone use over an extended period of time Having suffered trauma to the knee joint judged during clinical evaluation to have a significant effect on the presenting clinical condition. Physiotherapy or other similar treatment for patellofemoral pain syndrome within the previous 3 months

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