Tibial shaft fractures treated with the AO unreamed tibial nail

Tibial shaft fractures treated with the AO unreamed tibial nail S Kutty, M Farooq, D Murphy, C Kelliher, F Condon, JP McElwain Department of Trauma and Orthopaedics, The Adelaide and Meath Hospitals incorporating the National Children’s Hospital, Dublin, Ireland

Abstract Background The AO unreamed tibial nail (UTN) has been used for both open and closed tibial fractures. The reported results have been mixed. We evaluated its outcome in our unit. Aim To assess the outcome of tibial shaft fractures treated with the AO UTN. Methods Forty-eight patients underwent intramedullary nailing between 1995 and 2000 using the AO UTN. Followup details were available for 45 patients. Results Forty-four fractures united (97%). Complications included one non-union (2.2%), 15 delayed unions (33%), nine had either broken or bent interlocking screws (20%), six malunions (13%) and three patients underwent fasciotomy for compartment syndrome (7%). Twenty-one patients underwent at least one additional operation to obtain union (47%). Of these, five underwent exchange nailing (11%). Conclusions The AO UTN does have a high complication rate and, should it be used, we feel that early dynamisation or exchange nailing be considered to hasten union and prevent screw breakage.

Introduction Intramedullary nailing is the treatment of choice for most diaphyseal fractures of the tibia. It is pre f e rred to plate osteosynthesis because of its better mechanical pro p e rties and lower incidence of associated infections.1 Since the introduction of locked intramedullary nails, the indications have been extended to include comminuted fractures, fractures with an open medullary canal and more proximal and distal fracture s .2-6 Although reamed intramedullary nailing has been shown to have superior union rates, it is not fraught from complications.

Patients and methods Forty-eight patients with 48 fractures of the tibia underwent intramedullary nailing with the AO unreamed tibial nail. The period of study was 1995-2000. The study design was a re t rospective analysis of the group. A chart review and radiographic assessment was undertaken. Follow-up details were available for 45 patients with three being lost to follow-up and excluded. The indications for AO UTN in this series were closed or open tibial shaft fractures with significant soft tissue injury and displacement. All fractures were in the ‘nailing zone’ and did not include metaphyseal fracture s .

Operative protocol A standard operative protocol was obser ved in all cases. General anaesthesia was given to all patients. Third generation cephalosporins were administered intravenously in all cases. Patients with open fractures had the same antibiotic administered. The patient was positioned on the fracture table with a thigh support and a calcaneal pin was used for traction. The open fractures were treated with initial debridement and i rrigation with copious saline, followed by intramedullary nailing. The wounds were left open and underwent delayed Irish Journal of Medical Science • Volume 172 • Number 3

c l o s u re within a week. All the open fractures attained closure without plastic surgical pro c e d u res. The closed tibial shaft f r a c t u res were fixed in the following trauma list within 24 hours. Two locking screws were inserted through the targeting device attached to the nail proximally in every case. For distal locking, two screws were inserted with a free hand radioluscent t a rgeting device. All AO UTNs were locked in a static manner. Soft dressings were applied over the affected limb. They were treated with elevation and ice packs. Postoperatively, knee and ankle movements were encouraged to prevent reflex equines of the foot and a stiff knee. The patients were not allowed to weight bear on the affected limb. They were mobilised on crutches at 48 hours. The intravenous antibiotics were continued for a period of 48 hours for closed fractures and for five days for open fractures followed by oral antibiotics for a week. Compartment syndrome was diagnosed on clinical examination and compartment pre s s u re measurements. A Δp of less than 30mmHg was set for decompre s s i o n .7 Union was judged radiographically with the presence of m a t u re callus bridging the fracture on two radiographic views. The radiographs were assessed by two people including the consultant. Clinical assessment was judged by the ability of the patient to stand on the affected limb without pain. Failure to achieve union at six months after injury was defined as delayed union. With no evidence of union at nine months, the fracture was labelled a non-union.8 Malunion was labelled as any fracture with an angular or rotational malalignment of more than 5°. Regular radiographs of all patients identified an accurate time of f r a c t u re union.

Results T h e re were 35 males and 10 females whose mean age was 29.2 years (range 17-60). Of the 45 acutely displaced fractures, 10 w e re open. Three were Gustilo & Anderson Type I, three Type 141

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II and four Type III A. The mechanism of injury was sports related in 10, road traffic accident in 22, pedestrian (7) and other causes (6). All fractures were considered unstable because of significant displacement, comminution and fracture geometry. Of the 45 patients, 18 had multiple injuries. Associated injuries were upper limb fractures (6), lower limb f r a c t u res (4), pelvic injuries (3), chest injuries (5), abdominal injuries (5), head injuries (6) and facial injuries (2). The mean follow-up was 19 months (range 12-22). The hospital stay for isolated limb injury was 6 days (range 4-10) and that of the multiply injured was 20 days (range 18-40). Fortyfour fractures united; of these, 15 (33%) were delayed and eventually united. The delayed unions took between six to nine months to unite. The single non-union (2.2%) underwent an Ilizarov external fixator and bone transport. This patient was involved in a road traffic accident and sustained a Type III A f r a c t u re. There was a lot of soft tissue disruption that needed reconstructive surgery to obtain closure of the wound. A subsequent exchange nailing using the Grosse-Kempf (GK) nail with the reamed technique failed to obtain union. At 10 months post-surgery he underwent excision of the non-union fragment, application of Ilizarov external fixator and bone transport. Union was achieved at 18 months post-injury. The other complications included nine patients (20%) who had either bent or broken interlocking screws, six malunions (13%) and three patients (7%) underwent fasciotomy for compartment syndrome. These three patients had closed f r a c t u res that were comminuted and sustained due to high velocity road traffic accidents. The diagnosis was made at presentation of the symptoms that occurred in the postoperative period. The mean age of these three patients was 30.67 years (range 22-40). The fasciotomies were closed without the need for skin grafting and by about day 5. Twentyone patients (47%) underwent at least one additional operation to hasten union, most commonly dynamisation of a statically locked nail. Of these, five patients (11%) underwent exchange nailing with a GK nail using the reamed technique. Thre e patients of the open fractures had superficial wound infections, which responded to antibiotic treatment and cleared. They were diagnosed during their first review in the outpatients department. The antibiotic given was oral penicillin and flucloxacillin for a period of seven days. There were no complications related to the insertion of the calcaneal pin for traction.

hasten union and prevent implant failure. The UTN was originally developed as a temporary device for tre a t m e n t , treating severe open fractures with the expectation that exchange nailing would follow.16 Its routine use as a definite implant hasn’t yet been established. It is possible that its ro u t i n e use has resulted in unacceptable complications and one should keep in mind that its use is only temporary. Mulcahy and McElwain17 in a series of 112 tibial fractures showed an overall 99% primary union rate for both open and closed fractures fro m this institution. Since this study, our practice has changed towards reamed intramedullary nail for both closed and certain open tibial shaft fractures. References 1. 2.

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Discussion Court-Brown et al9 have shown for closed fractures and Keating et al10 for open fractures that reaming has better results. Reaming experimentally has shown to have adverse consequences such as haemostatic activation,11 systemic embolisation,12 reduced bone stre n g t h13 and destruction of endosteal blood supply14 and increased compartment pre s s u re s .7 This, however, has not nearly translated in clinical practice. T h e re has been a suggestion that reaming may worsen the compartment pre s s u res and perhaps trigger a full-blown compartment syndro m e .15 In our series, three patients (7%) underwent a fasciotomy for compartment syndrome. Our findings in this series support that the incidence of delayed union, non-union, malunion and implant failure is unacceptably high. The AO UTN provides a reliable initial stabilisation. Malunion can be minimised with meticulous technique. Care f u l post-operative care is essential. Early dynamisation can pre v e n t hardware failure. If an AO UTN is used, we feel that early dynamisation or exchange nailing should be considered to 142

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Correspondence to: Mr S Kutty, 46 The Old Forge, Lucan, Co Dublin. Email: [email protected] Irish Journal of Medical Science • Volume 172 • Number 3