Injury Vol. 26,No. 4. pp.275-276, 1995 Copyright (0 19% Elsevier Science Ltd

Printed in Great Britain. All rights reserved OOZO-1383/95 ~lO.OO+O.OO

Isolated complete rupture of biceps femoris tendon

Y. Fortems, J. Victor, D. Dauwe and G. Fabry Orthopaedic Department, University Hospital Pellenberg, Pellenberg, Belgium

Injury, Vol. 26, No. 4, 275-276, 1995

Introduction Traumatic complete rupture of the biceps femoris muscle tendon (MBFT) is a rare entity of which only two separate cases have been describedI,‘. Two more patients with different injury mechanisms are reported. One patient had a surgical repair of her tendon while the other was treated non-operatively. Both patients had a good clinical out- come and resumed their previous sporting and profes- sional activities.

Case reports Case 1 Running forwards, a 44-year-old amateur indoor soccer-player felt a sudden sharp pain at the back of his right knee when passing the ball backwards with the sole of the foot. He had never experienced pain in that knee previously. He was unable to resume the game. On arrival at the trauma unit he located the pain at the lateroposterior part of the knee. Clinical examination revealed a normal knee joint, but the posterolateral ridge formed by the MBFT was absent. A small painful lump could be palpated 3 cm proximal to the fibular head.

X-rays of the knee showed no abnormalities. Ultrasound confirmed a complete rupture of the MBFT 3 cm proximal to the fibular head associated with the presence of a small haematoma.

Because surgery was refused by the patient, non-operative treatment consisting of plaster of Paris immobilization for 3 weeks in 30” knee flexion was prescribed followed by intensive physiotherapy.

Four months after the initial injury the patient resumed his sporting activities. The tendon could not be palpated on the back of the knee. A Cybex isokinetic dynamomehy examination (Cybex isokinetic system LUMEX Inc. NY, USA) 6 months after the injury showed only a mid flexion (14 per cent) and extension (12 per cent) peak torque deficit compared to the other knee. The values of the normal left knee were consistent with the expected values for sex and age.

Case 2 A 42-year-old female fell forward over an outstretched leg on a slippery floor. She sustained a sudden flexion of the hips and extension of the left knee. She felt a sharp pain on the dorsal aspect of her knee. She was unable to walk on the affected leg and could not actively flex or extend the knee any more. On clinical

examination with the knee in 90” flexion the absence of the posterolateral ridge was noted. A haematoma was seen proximal to the fibular head. X-rays of the knee were normal, and ultrasound and magnetic resonance imaging confirmed complete rupture of the biceps femoris tendon 2 cm from its insertion.

A surgical repair with resorbable sutures was performed. This was protected with plaster of Paris for 4 weeks and followed by intensive physiotherapy. A Cybex isokinetic dynamometry examination was performed after 6 months. The tendons could be felt at that time. This showed a marked decrease in flexion (48 per cent) and extension (31 per cent) peak torque compared with the confralateral knee. All values for both left and right were well below normal values for sex and age.

Discussion Owing to the association of its anatomical position spanning the hip and knee joint and its antagonistic action, the powerful musculus quadriceps femoris predisposes the MBF to musculotendinous lesion?. Distal tendinitis of MBFT due to repetitive overstretching is a frequent entity in our sports clinic. Typically these middle-aged amateur sporters complain of pain on the posterolateral aspect of the knee during or after the game. These over-use lesions do not usually lead to spontaneous rupture of the MBFT.

An injury in which a combination of sudden flexion of the hip and extension of the knee is elicited is necessary to cause complete traumatic rupture of the distal part of the MBFT’. This mechanism, described in waterskiers in which the skies are stuck in a wave and the upper body is pulled forward by the towing rope, is present in a reversed form in Case 2.

Another injury mechanism was present in Case 1. Involuntary co-contraction of the MBF and M. quadriceps femoris leading to spontaneous tendinous rupture of the former, has never been described before to our knowledge. The cricket player described in the paper by F. McCol- drick’ suffered a spontaneous rupture while running straight. Our patient tried unsuccessfully to combine running and a backwards pass, thereby simultaneously contracting hamstrings and knee extensors.

It is interesting to note the peak torque values of Case I show only mild decrease of values 6 months after the injury while Case 2, who had been operated on, still showed marked decrease of peak torque values. Both patients were pleased with the final outcome.

Although the literature advocates surgery”z, non-

276 Injury: International Journal of the Care of the Injured Vol. 26, No. 4, 1995

operative treatment, consisting of plaster of Paris immob- ilization for 3 weeks in 30” knee flexion, might also have its value in the treatment of this rare condition.

2 Verburgh H and Keeman JN. Complete ruptuur van de musculus biceps femoris pees. Ned Tijdschr Geneesk 1991; 135(42): 1970.

Paper accepted 22 November 1994.

References 1 Coldrick F and Colville J. Spontaneous rupture of biceps

femoris. Arch Orthop Traum Surg 1990; 109: 234.

Requests for reprints should be addressed to: J. Victor, Orthopedie, University Hospital Pellenberg, Weligerveld 1, B-3212 Pellen- berg, Belgium.