398 Injury (1990) 21, 398-400 Printed in Great Brifuin

injury of knee ligament associated with ipsilateral femoral shaft fractures and with ipsilateral femoral and tibia1 shaft fractures

M. J. Szalay, 0. R. Hoskmg and P. Annear The Royal Perth Hospital, Perth, Western Australia Sir Charles Gairdner Hospital, Perth, Western Australia

A series of 7 10 patients with 114 fracfure of the femur were reviewed an average of 3.9 yews after injuy. Demonstrable knee ligament kzxity was present in 31 (227 per cent) of these pafien fs, while 13 (11 per cent) complained of instability. Thirty-three patients with 34 ipsikateral femoral and tibial shaft fmc&res were examined ati average of 3.7 years after injuy. Demonstrable knee ligament kzrity was present in 18 (53 per cent) of these patients, while 6 (18 per cent) complained of instability.

Most of the patients with instability had a rupture of the anterior cruciate ligament with or without damage to other ligaments.

We conclude that knee ligament injuy is more common with ipsilaferal fracture of the femur and fibia than with just a single ipsikzteral femoral fracture. We advocate careful assessment of the knee in all cases of fracture of the femur.

Introduction

Most fractures of the shaft of the femur are caused by high-energy trauma. It would be expected that in many cases the ipsilateral knee ligaments are subjected to severe stress. In the presence of a mobile fracture of the femur, examination of the knee is difficult. Knee swelling due to haemarthrosis may be mistaken for a sympathetic effusion. Previous studies have reported that the incidence of knee ligament injury associated with femoral shaft fracture is between 33 and 70 per cent (Dunbar and Coleman, 1978; Walker and Kennedy, 1980; Walling et al., 1982; Lakshman and Scotland, 1985).

Ipsilateral fracture of the femur and tibia is regarded as a serious injury with a poor prognosis. Patients treated non-operatively fare badly with a high incidence of malunion, non-union and knee stiffness (Fraser et al., 1978). Veith et al. (1984) found that internal fixation of both fractures improved results, but a number of patients have residual symptoms and poor function. Some of the poor results are due to the fractures themselves but many have unstable knees.

In this study, we sought to establish the incidence and type of knee instability occurring in patients with femoral fractures alone, or ipsilateral fractures of the femur and tibia, at long-term follow-up.

0 1990 Butterworth-Heinemann Ltd 002O-1363/90/060398-03

Materials and methods

A multicentred study was performed at the St George and Sutherland Hospitals (Sydney) and the Sir Charles Gairdner, Royal Perth, and Fremantle Hospitals (Perth). The medical records of patients with fractures of the femoral shaft presenting to these hospitals between 1978 and 1987 were studied. Patients aged under 16 years or over 45 years, those with previous knee injury, and those with an intra-art&u fracture of the knee were excluded.

Patients were contacted by letter or telephone and asked to attend for examination. Details of the injury and treatment were extracted from the hospital records. The patients were asked whether the knee was unstable and, if so, what level of activity precipitated giving way of the knee, how they managed stairs, and whether their knee caused any other restriction of their daily activities. Clinical tests performed on all patients were the Lachrnann, anterior and posterior draw at 90 of flexion and in internal and external rotation of the knee, valgus and varus stress at 0 and 30 flexion, pivot shift and reverse pivot shift, and the external rotation recurvatum test (Hughston and Norwood, 1980). Findings were graded normal, mild laxity or marked laxity.

Patients were subsequently classified as having important or unimportant instability on the basis of their symptoms. Those with important instability had symptoms which interfered with their daily activities, such as giving way while walking, or being able to negotiate stairs only by holding onto a rail. If the patient had laxity on examination but no episodes of giving way or limitation of daily activity, they were classified as having unimportant instability.

The x2 test with a Yates correction was used to assess statistical significance.

Results

A total of 344 medical records were reviewed. Of these, 143 patients presented for examination.

In the group with femoral fractures alone, I10 patients with 114 fractures were examined. There were 82 males and 28 femdes. The average age was 22 years (range 16.3-45.5

Szalay et al.: Knee ligament injury with femoral and tibiai shaft fractures 399

years). The average follow-up was 3.9 years (range 6 months-II.7 years).

Thirty-three patients with 34 ipsilateral femoral and tibia1 shaft fractures were reviewed; 27 were male and 6 female. Mean age was 23.3 years (range 16-41.3 years). Average follow-up was 3.7 years (range 6 months-10 years). The cause of injury in both groups is shown in Table I. In the group with femoral fracture alone, an equal number were injured in motor car and motorcycle accidents. Of those sustaining ipsilateral femoral and tibial fractures, the majority were injured in motorcycle accidents.

The methods of treatment in both groups are shown in TableII and Table III. The incidence of knee laxity in the 17 patients treated with tibial traction was not significantly different to the incidence in the ,group treated with internal fixation.

Table I. Mode of injury

Motor car Motorcycle Fall Athletics

Total

lpsilateral femoral fracture alone

48 48 10 4

110

Ipsilateral fracture

of femur and tibia

10 23

33

Table II. Treatment of femoral fractures

Intramedullary nail Plate External fixator Non-operative Combination

71 23

2 14 4

Table III. Treatment of kachre of femur and tibia

Internal fixation both fractures 17 Fixation of femur with splintage of tibia 8 Fixation of femur with external fixator tibia 6 Non-operative treatment of both fractures 3

TabIe IV. Types of knee laxity

At follow-up, 31 of the group with femoral fractures alone (27 per cent) had demonstrable laxity in the ipsilateral knee while 13 (11 per cent) were classified as having important instability. AU patients with important instability showed anterior rotary laxity. There were no patients with isolated collateral laxity. In the group with ipsilateral fractures of both femur and tibia, 18 (53 per cent) of the 34 knees had clinicaIly detectable knee laxity and in six (18 per cent) this was graded as important. Laxity of ihe posterior structures was more common in this group than in patients with femoral fracture alone. The type of ligament laxity in both groups is summarized in TableN. Of the patients classified as having unimportant laxity, five were func- tionally limited due to other complications of the fractures. These were ankle equinus and stiffness, foot drop and malunion.

The difference in incidence of ligament laxity between the group with fractures of the femur and tibia and those with femoral fracture alone was found to be shtistically signifi- cant (PC 0.01). The incidence of important instability was not found to be significantly different in the two groups.

Discussion

Knee ligament injury occurring in association with ipsilateral femoral shaft fracture is well documented. Pedersen and Serra (1968) first reported this combination of injuries in a series of six cases. Dunbar and Coleman (1978) prospect- ively examined 20 patients and noted a 25 per cent incidence of important instability, while 70 per cent of knees showed detectable laxity at the time of injury. Walling et al. (1982) assessed knee stability at the time of injury in 24 patients by inserting a pin through the distal femur. Eight patients showed ligament laxity, all but two having anterior cruciate ligament rupture, with or without laxity of other ligaments. Walker and Kennedy (1980) reviewed 54 patients retrospectively and found laxity in 26 knees (48 per cent). Of these, 16 showed damage to the anterior cruciate ligament; 30 per cent of the knees were classified as being significantly unstable.

Fraser et al. (1978) reviewed 63 patients with fracture of the femur and tibia and found that 39 per cent showed laxity, with one-third of these having important symptoms. Some of the patients had intra-articular fractures involving the knee and the type of ligament laxity was not specified.

To our knowledge, there has been only one published

Femur fracture only Femur and tibia (N=114) fracture (N = 34)

Important Unimpoflant Important Unimportant

ALRI 6 7 2 4 AMRI 1 2 PLRI 1 ALRI and AMRI 4 6 1 3 ALRI and PLRI 2 PLRI and posterior 3 AMRI, ALRI and PLRI 3 Lateral 1 Posterior 2 1

Total 13 18 6 12

ALRI =Anterolateral rotary instability AMRI =Anteromedial rotary instability PLRI = Posterolateral rotary instability

400 Injury: the British Journal of Accident Surgery (1990) Vol. Zl/No. 6

study comparing the incidence of knee ligament injury in patients with important instability showed anterior rotary patients sustaining ipsilateral fracture of the femur with laxity. We advocate examination of the knee under anaes- those suffering ipsilateral fracture of femur and tibia. thesia in all patients with fracture of the shaft of the femur.

Lakshman and Scotland (1985) found demonstrable laxity in II of 21 patients with a fracture of the femur alone, of whom five were symptomatic. Of seven patients with ipsilateral fracture of femur and tibia, all showed laxity but only three were symptomatic. Medial ligament and poster- ior capsule tears were the most common injuries detected.

Acknowledgement

The authors would like to thank Mr Alan Skirving for his assistance in the preparation of the manuscript.

The rate of knee ligament laxity associated with fractures of the femur in our series is lower than most of the previous studies. Important instability, also, was less common than has been previously reported. All but three patients with detectable laxity in the femoral fracture group showed anterior rotary laxity alone or in combination with other laxity patterns. This is in agreement with previous studies which have shown a high incidence of anterior cruciate ligament injury.

References

Dunbar W. H. and Coleman S. S. (1978) Occult knee injuries associated with ipsilateral femoral fractures. A prospective study. Orthop. Trans. 2,253.

Fetto S. J. and Marshall J. L. (1980) The natural history and diagnosis of anterior cruciate ligament insufficiency. Clin. Orthop. x47,29.

Detectable ligament laxity was significantly more common in patients with ipsilateral fracture of the femur and tibia than with fracture of the ipsilateral femur alone. The difference in incidence of symptomatic instability between the two groups was not significant. However, six of the 12 patients in the group classified as having unimportant instability were restricted by other complications of their fractures. It may be that they would have had a sympto- matically unstable knee with normal use of the limb.

Only one case of isolated collateral laxity was identified in the whole series. In several previous reports (Pedersen and Serra, 1968; Walling et al., 1982) collateral laxity was common. There is evidence that collateral ligament tears heal without surgical repair (Hastings, 1980; Sandberg et al., 1987). Our patients may have suffered collateral injury which healed spontaneously. On the other hand, knees with rupture of the anterior cruciate ligament and rotary instabi- lity rarely stabilize with time (Fetto and Marshall, 1980).

Fraser R. D., Hunter G. A. and Waddell J. P. (1978) Ipsilateral fracture of the femur and tibia. 1. Bone anA joint Sung. 60B, 510.

Hastings D. E. (1980) The nonoperative management of collateral ligament injuries to the knee joint. Clin. Orthop. 147,22.

Hughston J. C. and Norwood L. A. (1980) The posterolateral drawer test and external rotation recurvatum test for postero- lateral rotary instability of the knee. C/in. Orthop. 147, 82.

Jonsson T., Althoff B. O., Peterson L. et al. (1982) Clinical diagnosis of ruptures of the anterior cruciate ligament: A comparative study of the Lachmann test and anterior draw sign. Am.]. Sports Med. 10, 100.

Lakshman K. and Scotland T. R. (1985) The incidence of knee ligament injuries in 105 patients with lower limb fractures. J Bane and]oint Sutg 67B, 151.

Pedersen H. E. and Serra J. B. (1968) Injury to the collateral ligaments of the knee associated with femoral shaft fractures. C/in. Orthop. 60, 119.

Whilst the treatment of anterior cruciate ligament injuries is controversial, we believe it is important to diagnose ligament injuries associated with femoral fracture early to allow an appropriate rehabilitation programme to be insti- tuted. The presence of an effusion should alert the clinician to the possibility of knee ligament injury. The Lachmann test has been shown to be almost 100 per cent diagnostic of anterior cruciate ligament tear when performed under anaesthesia (Jonsson et al., 1982). Rigid fixation of fractures allows more accurate assessment of the knee.

Sandberg R., Balkfors B., Nilsson B. et al. (1987) Operative versus nonoperative treatment of recent injuries to the ligaments of the knee. J Bone and]oint Sutg 69A, 1120.

Veith R. G., Wiiquist R. A. and Hansen S. T. (1984) Ipsilateral fractures of the femur and tibia. 1. Bone and]oint Swg. 66A, 991.

Walker D. M. and Kennedy J. C. (1980) Occult knee injuries associated with femoral shaft fractures. Am. ]. Sports Med. 8, 172.

Walling A. K., Seradge H. and Spiegel P. G. (1982) Injuries to the knee ligaments with fractures of the femur. 1. Bone adJoint Surg. 64/i, 1324.

In conclusion, this study revealed that 27 per cent of patients with femoral shaft fractures showed detectable knee laxity at long-term follow-up, while II per cent showed important instability. Following ipsilateral fracture of the femur and tibia, 53 per cent had detectable knee laxity and 18 per cent showed important instability. Most of the

Paper accepted 29 January 1990.

Requests for reprints shouM be aailressed to: Dr M. Szalay, Orthopaedic Registrar, Royal Perth Hospital, PO Box x2213, GPO Perth WA 6001.