Department of Rheumatology, Musgrave Park Hospital, Stockmans Lane, Belfast BT9 7JB, UK
SIR, A 14-yr-old schoolgirl presented with a 2-month history of a painful right shoulder. She related its onset to carrying her heavy schoolbag. The pain was insidious in onset, progressed over 6 weeks and then plateaued. She pointed to the region of the right acromion when describing the pain and reported it sore to touch. On initial inspection the appearance of the shoulder was satisfactory. She was tender to palpation of the right acromioclavicular joint and the posterior aspect of the acromion. There was a full range of shoulder joint motion, but there was pain on internal rotation and at the limits of flexion and abduction. X-ray of the right shoulder showed increased irregularity of the right apophysis, in keeping with apophysitis (Fig. 1). Isotope bone scan showed an increase in isotope in the region of the right acromion compared with the left (Fig. 2
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Apophyseal injuries are more common in adolescence, when growth spurts occur, because of the increase in tension of muscles and tendons about the apophysis. The tensile force caused by repeated contraction of the attached muscles can result in an overuse injury [2]. The most common example is OsgoodSchlatter disease, which is caused by the force of repeated quadriceps muscle contraction at the point of insertion of the patellar tendon to the developing tibial tuberosity [3]. X-ray changes include collapse, sclerosis, fragmentation and changes in bony contour. Isotope bone scan can show increased uptake in the area [4].
Conservative treatment is all that is usually necessary, with an explanation being given, rest of the affected part, physiotherapy and analgesia. The condition usually resolves with skeletal maturity and cessation of growth of the apophysis.
There are very few case reports of acromial apophysistis [4, 5]. No overuse injury around the shoulder associated with carrying a schoolbag has been reported in the literature. We propose that contraction of the deltoid muscle against the pressure of a heavy schoolbag caused enough tension at the insertion point into the acromion to result in an apophysitis. Although this is an unusual site, it is important to recognize that overuse injuries are a cause of shoulder pain in adolescence.
Notes
Correspondence to: D. A. Moyes
References