View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Injury Extra (2006) 37, 31—33 www.elsevier.com/locate/inext CASE REPORT Isolated avulsion fracture of the lesser tuberosity of the humerus associated with delayed axillary nerve neuropraxia Vinod Kumar *, Jaime Candal-Couto, Amar Rangan Shoulder and Elbow Unit, Department of Trauma and Orthopaedics, James Cook University Hospital, Middlesbrough, TS4 3BW UK Accepted 27 June 2005 Introduction shoulder, following a stumble down a flight of stairs, whilst at work. On initial examination, there was We report a patient with an avulsion fracture of the limitation of movements in all directions due to lesser tuberosity of the humerus, associated with a pain. No ‘signs or symptoms of axillary nerve injury delayed axillary nerve neuropraxia. Isolated avul- were noted. Antero-posterior and axillary lateral sion fractures of the lesser tuberosity are rare and radiographs of the left shoulder revealed an avulsion have been reported, but, to our knowledge, there fracture of the lesser tuberosity of the Humerus are no previous reports of this injury associated with (Fig. 1). He was referred on to the orthopaedic an axillary nerve palsy. The avulsion fracture was department for further management and a compu- treated with open reduction and internal fixation of terised tomography (CT) scan was arranged to the fragment, which led to complete resolution of delineate the fracture fragments and to rule out the axillary nerve neuropraxia. We emphasise hav- any other injuries around the shoulder joint. When ing a high index of suspicion, and prompt fixation of assessed 3 weeks later by the specialist shoulder the fracture, when identified to prevent develop- team, active internal rotation at the shoulder was ment of a axillary neuropraxia. painful and limited in range. There was also weak- ness of internal rotation and the patient was unable to lift the dorsum of hand off the lower back. Gerber Case report and Krushell described this test, and the inability to perform this manoeuvre reflects weakness of the A 43 year old, right hand dominant male presented subscapularis muscle (the lift-off test).1 The gleno- to the accident and emergency department in our humeral joint was stable on application of stress. hospital, with pain and difficulty in moving his left There was marked paraesthesia along the axillary nerve distribution. The deltoid had grade three * Corresponding author at: Department of Trauma and Ortho- power, but with contraction palpable in all three paedics, James Cook University Hospital, 20 The Wickets Memor- parts. The patient clearly reported the onset of ial Drive, Stokesley Road, Marton-in-Cleveland, TS7 8EL, UK. Tel.: +44 1642 325733; fax: +44 1642 854375. axillary nerve symptoms to 3 weeks after injury. E-mail address: [email protected] (V. Kumar). The scan report confirmed an isolated avulsion 1572-3461# 2005 Elsevier Ltd. Open access under the Elsevier OA license. doi:10.1016/j.injury.2005.06.055 32 V. Kumar et al. gery, the axillary neuropraxia had improved and at 6 weeks, the neuropraxia had completely resolved. The patient was then commenced on active resis- tance exercises for strengthening internal rotation of the shoulder. No complications were noted. Discussion Fracture of the lesser tuberosity of the humerus is usually associated with either proximal humerus fractures or shoulder dislocations. Isolated avulsion fractures of the lesser tuberosity of the Humerus are exceptionally rare. This entity has been reported in patients as young as twelve6 to those at the age of 3 Figure 1 Antero-posterior radiograph of the shoulder 54. Fracture of the lesser tuberosity associated with arrow showing the lesser tuberosity fragment. with a delayed axillary neuropraxia has not been reported in literature to our knowledge. The axillary nerve arises from the posterior cord of the brachial fracture of the lesser tuberosity with the fracture plexus and winds around the inferior border of the fragment displaced anteriorly and inferiorly. The belly of subscapularis. The delayed neuropraxia, we gleno-humeral joint was found to be intact. believe was due to the gradual pull of the tendon of The patient underwent surgery for fixation of the subscapularis along with the avulsed lesser tuber- avulsed lesser tuberosity fragment. On examination osity fragment, thus causing an increasing stretch on under anaesthesia, no instability was detected. An the axillary nerve (Fig. 3). Nerve injuries associated anterior delto-pectoral approach was used, the with fractures around the proximal humerus recover axillary nerve was found to be tented under the well but they prolong recovery and also restoration subscapularis tendon, which was attached to the of function after such fractures.4 The mechanism of avulsed fragment. The displaced lesser tuberosity injury, as stated by Haas,2 occurs when a strong fragment was reduced and fixed with a single fully external rotatory and abduction force is applied threaded cancellous screw and a bony anchor, to its while the arm is in the position of maximum external anatomical bed (Fig. 2). rotation and about 608 of abduction. This force Post-operatively, the shoulder was supported in a causes an avulsion of the subscapularis with a frag- sling and passive assisted pendulum exercises were commenced, with restriction on external rotation and active internal rotation. At 2 weeks, post sur- Figure 2 Antero-posterior radiograph of the shoulder Figure 3 Three dimensional computerized tomography with the lesser tuberosity fragment fixed with a cancellous reconstruction: line indicating the course of the axillary screw and anchor. nerve. Isolated avulsion fracture of the lesser tuberosity 33 ment of the lesser tuberosity. Although, standard prompt fixation of the fracture fragment, this allows antero-posterior radiographs show large fragment, return of function and can prevent complications axillary lateral view may be required to demon- such as the one in our case report. strate a smaller fragment. A computerised tomo- graphic scan (CT) may be required to rule out any associated injuries around the shoulder. Delayed References diagnosis, of more than a year, of an isolated avul- sion fracture of the lesser tuberosity and successful 1. Gerber C, Krushell RJ. Isolated rupture of the tendon of the treatment with osteotomy and realignment of the 5 subscapularis muscle. Clinical features in 16 cases. J Bone displaced fragment has been reported, but these Joint Surg 1991;73B(3):389—94. were not associated with any nerve injury. 2. Haas SL. Fracture of the lesser tuberosity of the humerus. Am J Fracture of the lesser tuberosity of the Humerus Surg 1944;63:253—6. can easily be missed on a plain antero-posterior 3. McAuliffe TB, Dowd GS. Avulsion of the subscapularis tendon. A case report. J Bone Joint Surg 1987;69A:1454—5. radiograph and hence we emphasise having a high 4. Paschal SO, Hutton KS, Weatherall PT. Isolated avulsion frac- index of suspicion and highlight the role of an ture of the lesser tuberosity in adolescents. A report of two axillary lateral radiograph as a standard post trauma cases. J Bone Joint Surg 1995;77A(9):1427—30. series of the shoulder. A CTscan can help to show the 5. Visser CP, Coene LN, Brand R, Tavy DL. Nerve lesions in displacement of the fracture fragment. A displaced proximal humeral fractures. J Shoulder Elbow Surg 2001;10(5):421—7. fragment can not only limit the shoulder function 6. White GM, Riley Jr LH. Isolated avulsion of the subscapularis but can also cause stretching of the axillary nerve, insertion in a child. A case report. J Bone Joint Surg as demonstrated in our report. We recommend 1985;67A:635—6..