Ecrst and Celztr611Afdca?z,Jozininl of Szizrrgcy Vol. 4, No. 2

Avulsion of subscapularis muscle tendon leading to recurrent anterior dislocation of the shoulder

L N Gakuo MMed Serzior Leclrrrer Dep:~rtn~entof Orthopaedic Surgery Univers~tyof Nairobi

Key words: sho~~lder,recurrent dislocation, subscapularis tendon avulsion.

Fifteen patients, ten males and five females, Velpenu bandage before mobilisation and were identified as having recurrent anterior physiotherapy. In two patients the dislocation of the shoulder after trauma due to subscapularis tendon was frayed and could not avulsion of the subscapularis muscle tendon take sutures and therefore an allograft of tendo from its humeral attachment. The usual Achilles was used. mechanism of injury was traumatic hyperextension or external rotation of the The patients have been followed up for an abducted arm. The right arm was involved in average of three years postoperatively. All have 12 patients and the left arm in only three acceptable functional results but a reduced patients. range of external rotation.

The presenting symptoms were pain and Introduction weakness of the affected shoulder. Physical In 1834, Smith reported a case in which he found a examination showed reduction of the passive tear of the subscapularis tendon from the lessor range of joint movement and tenderness on the tuberosity with anterior dislocation of the shoulder anterior aspect at the shoulder at the level of while all the other muscles were intact1. Among the intertubercular groove and a reduced range the rotator cuff tears, isolated subscapularis tendon of internal rotation of the shoulder. The tears are rare213 and tend to occur in young active diagnosis was suspected from the history, individllals. They usually give a history of trauma physical examination and radiographs and was and present with pain followed by functional finally confirmed by surgical exploration. disability. The dislocation is easily reduced by the patient or medical personnel but keeps recurring The ages of the patients ranged from 20 to 46 thereafter either spontaneously, after minor trauma, years (mean 33 years). The dislocation was or any activity involved abduction and external found to be due to a complete tear of the rotation. The actual tear is difficult to diagnose subscapularis tendon (12 patients) and partial clinicallf and needs further confirmatory procedures tears in three patients, without fracture of the by ultrasound, computerised tomographic scanning, lesser tuberosity in any of the patients. magnetic resornnce imaging or arthroscopy, if these The repair consisted of mobilisation of the facilities are available. In our circumstances are subscapularis muscle and its reinsertion into depend mainly on history and physical examination an osseous trough created in the humerus. The and confirm the diagnosis by surgical exploration. shoulder was splinted for six weeks in a Patients and methods A series of 15 consecutive patients, seen and treated by the author between 1988 and 1993 is reported. Aclclress for corresponclence: Dr L N Gakuu MMed, Senior Lecturer, Dep:~i~mentof Orthopaedic Surgery, University of Nairobi, P 0 Box 55164 Nairobi, Kenya. The l~istory,pl~ysical findings, racliographs and the operations clone were analyzed.

OPERATIVE TECHNIQUE Under general anaesthesia, an incision was made along the deltoid groove from the clavicle clistally fol- about 10cm. the pectoralis ~najor,the deltoid, the coracobrachialis and biceps were retracted thereby exposing the subscapularis muscle. The subscapularis lnuscle was founcl to be torn from its attachment to the humerus and retracted meclially (Fig 1 a & b). The capsule of the shoulder joint was then exposed ancl movements done to verify its strength. The glenoicl was palpated to rule out glenoicl tears, while the hurneral head was palpated to iule out a Hill-Sachs lesion. The biceps tendon was freed from its bicipital groove ancl retracted M. rubscapularis meclially. (torn) A sharp osteotome or oscillating saw was used to cut a groove in the humerus about lcm lateral to FIG lb Opemliuefiir?dir?gsshowing /eats of the srrl~scnprr1~1r.i~rnrrscic~ tei7don the bicipital groove 4cm long and Icm deep. An oblique tunnel was made about lcm lateral to this groove so as to connect with the groove. The torn capsule was loose this was also shortened as in the retracted subscapularis tendon was then freecl and Putti-Platt operation! In two patients, a tendon drawn under the biceps tendon into the groove. allograft from the tendo Achilles was appliecl Here it was fixecl to the bone with mattress sutures because the subscapularis tendon w:ls frayed and which were passed through the tunnel created in could not stretch enough or take sutures. the bone, over the bridge of the bone ancl again fixecl to the tendon and tied (Fig 2). During the last The arm was splinted with a Velpeazr bandage for step the humerus was kept in internal rotation so six weeks. Exercises to strengthen the internal that the subscapularis tendon firmly reinforced the rotator muscles were startecl at six weeks. capsule of the sl~oulclerjoint in this area. If the Results Coracoid process The patient's ages ranged from 20 to 46 years (mean 33 years). There were ten Inen and five women

Repair /r

I M. subsc;~pul;~ris (2 and 3 repaiwd)

Long hced m biceps Long he& of '>. m. hicepq \, \ '::-

FIG 2 The coinpletcd repair. (I\I:F;2:1). The right arm was affectecl in 12 patients investigations such as ultl-asouncl" computerised :~nclthe left in tl~ree.At operation, 13 patients hacl tomography (CT) scanning"', magnetic resonance complete tears while two had partial tears involving imaging"~'~ancl arthroscopf, where such k~cilities the bigger portion of the upper sicle of the are available. \Ve clepenclecl lnainly on the history, subscapu1;uis tenclon. careful physical examination, plain radiographs (to rule out Hill-Sach's lesions) and confirmed the The causes of the injuries were sports, roacl traffic diagnosis by surgical exploration. At exploration, acciclents ancl grancl 1na1 epilepsy (Table I) other causes of recurrent clislocation are lool

Cause Patients The failure of our treattnent in one patient in whom Sports 11 the clislocation recurred, suggests that it is aclvisable Volleyball 3 to shorten the capsule as is clone in the Putti-Platt Football 3 Rugby 2 operationhr to suture the capsule to the glenoicl Lawn tennis 3 rim as is done in Banltast's operationI3 in adclition

Road traffic accidents 2 to the repair of the subscapularis tenclon.

Grand ma1 epilepsy 2 The patient who clevelopecl sepsis hacl

TOTAL 15 i~i~n~unosuppl-ession.We suggest that patients going for bony surgely should be screenecl for imnlune status after inforinecl consent ancl counselling.

\\!as acceptable with no recurrence in fourteen References ptients but all had a reclucecl range of external 1 Smith J G. P:~thologicalnppealxnce of seven c:lses of rotation. injury of the shoulcler joints, with ren~arl:lcl