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Practice Practice Pointer

Patellofemoral pain

BMJ 2015; 351 doi: (Published 04 November 2015) Cite this as: BMJ 2015;351:h3939

Rapid Response:

Patellofemoral pain is a symptom, not a diagnosis

We read with interest the paper from Crossley et al on the diagnosis and treatment of patellofemoral pain (BMJ 2015;351:h3939). However we disagree with the diagnostic labelling and treatment strategy recommended by the authors. Anterior knee pain may be caused by a number of specific conditions which were identified over 25 years ago using clinical skills and plain radiographs including subdivisions of dysplasia, instability and arthrosis [1]. Additionally a recent meta-analysis of the relationship of anterior knee pain to patellofemoral imaging features has shown that imaging is required as part of the diagnostic pathway [2].

Neglecting features of dysplasia [3], instability [4] or arthrosis [5], will do no service to the sufferer who will certainly still have them after the 'effective' conservative treatment advanced by the authors. In a randomised trial, the same authors conclusively showed that advice alone had as large a treatment effect as any other conservative intervention. Knee surgeons have known for some time that for some indications, sham interventions are as effective as real ones [6]. In an ORUK funded study we are hoping to find some of the answers [7], based upon objective rather than subjective assessment of anatomy [8], kinematics [9] and joint health [10].

Our bottom line for sufferers from anterior knee pain reads rather differently from the one published in this review:

1. Objective diagnosis including imaging, will help decide why the problem developed, and what therapeutic options exist.
2. Conservative treatment of persisting instability, dysplasia or arthosis is no more effective than sham.
3. Sufferers from dysplasia or instability should seek early referral to a specialist.

1 Merchant AC. Classification of patellofemoral disorders. Arthroscopy 1988;4:235–40. doi:10.1016/S0749-8063(88)80037-9
2 Drew BT, Redmond AC, Smith TO, et al. Which patellofemoral joint imaging features are associated with patellofemoral pain? Systematic review and meta-analysis. Osteoarthr Cartil 2015;:1–13. doi:10.1016/j.joca.2015.09.004
3 Smith TO, Davies L, Toms AP, et al. The reliability and validity of radiological assessment for patellar instability. A systematic review and meta-analysis. Skeletal Radiol 2011;40:399–414. doi:10.1007/s00256-010-0961-x
4 Mäenpää H, Huhtala H, Lehto MUK. Recurrence after patellar dislocation. Acta Orthop Scand 1997;68:424–6.
5 Davies AP, Vince AS, Shepstone L, et al. The radiologic prevalence of patellofemoral osteoarthritis. Clin Orthop Relat Res 2002;:206–12.
6 Moseley JB, O’Malley K, Petersen NJ, et al. A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the Knee. N Engl J Med 2002;347:81–8. doi:10.1056/NEJMoa013259
7 Hing CB, Cobb JP. 512 - Surgery for patellar instability: the impact of pathomorphology on kinematics and gait. Orthop. Res. UK Res. Proj. 2015. (accessed 20 Nov2015).
8 Iranpour F, Merican AM, Dandachli W, et al. The geometry of the trochlear groove. Clin Orthop Relat Res 2010;468:782–8. doi:10.1007/s11999-009-1156-4
9 Auvinet E, Multon F, Meunier J. New lower-limb gait asymmetry indices based on a depth camera. Sensors (Basel) 2015;15:4605–23. doi:10.3390/s150304605
10 Hing CB, Smith TO, Donell ST, et al. Surgical versus non-surgical interventions for treating patellar dislocation ( Review ). Cochrane Rev 2012;:45.

Competing interests: No competing interests

14 December 2015
Arash Aframian
Clinical Research Fellow
Boughton O, Auvinet E, Iranpour F, Harris S, Hing CB, Cobb JP
St George's University, London and Imperial College, London