Medico-legal Aspects of Adult Tibial Shaft Fractures

Fracture of the tibial shaft is a common injury. There is a bimodal distribution of incidence. The mechanism of injury is usually high-energy trauma or sports injury in the young, and fall from a standing height in the elderly. The long term outcome from such injuries is of great importance when preparing medico-legal reports. Recently results after 12-22 (mean 17) years, including functional outcomes, have been reported.

Fractures are graded by multiple different systems in the literature. Gaston et al reviewed AO fracture classification, Winquist-Hansen grade, open and closed injuries, fracture displacement, Tscherne Score, location of fracture and associated fibula fracture in an attempt to find a prognostic correlation with outcome. These factors may be significant in predicting closed plaster or bracing treatment outcomes, but fragmentation and initial displacement of fractures are not reliable indicators of outcome when fractures are treated with intramedullary nailing.

Open fractures are usually graded after Gustilo and Anderson. Approximately 20% of open fractures are Grade 1; 25% are grade 2 and 55% are grade 3. Of the grade 3 open fractures, approximately 45% are grade IIIA, 50% are grade 111B and 5% are grade IIIC2 4 The majority of open fractures unite. The literature reports a range of non-union from 0-17%, the majority reporting around 4%. There is no clear breakdown of non­ union rates between Gustilo grades.

Treatment

Treatment of tibial shaft fractures may be through plaster immobilisation, functional bracing, intramedullary nailing, plating, or primary amputation in the unsalvageable limb. Undisplaced transverse fractures may be treated non-operatively, however, the majority of displaced fractures in the UK are treated operatively in 2014.

Fracture Union

Time to fracture union can be influenced by the severity of the injury and the treatment method. In a meta-analysis of 2372 trials, the time to union varied slightly with fixation device, but there was no difference in the number of fractures united at 20 weeks, or the incidence of non-union between treatment devices. However, caution should be exercised when interpreting such data as the more severe injuries may have been nailed. Primary union occurs without further intervention in over 90% of tibial shaft fractures. Some require further interventions such as bone grafting, exchange nailing, removal of locking screws and alternative fixation methods.

Compartment syndrome

Compartment syndrome is a potentially devastating complication of tibial shaft fracture. The intra­ compartment pressures are related to the extent of the associated soft tissue injury. Even in open fractures the associated soft tissue injury can cause a compartment syndrome. The incidence of compartment syndrome is reported from 1.6 - 9%. However, true comparisons between case series are difficult due to lack of criteria for diagnosis and severity.  There is a huge clinical difference between early decompression of oedematous muscle that responds and recovers fully, and excision of necrosed dead muscle as a lifesaving measure or the later formation of ischaemic contractures. However, all can be labelled compartment syndrome. We found an 11.5% fasciotomy rate, but no functional difference between those who underwent fasciotomies and those who did not at mean 17 years follow-up. The majority of the patients in this series had compartment pressure monitoring, so it was likely that timely intervention was undertaken before irreversible muscle necrosis occurred.

Knee and Ankle Symptoms

Stiffness of the knee or ankle may occur after tibial shaft fracture. This was a more prominent immediate feature when the knee, ankle and subtalar joint were immobilised for protracted periods by plasters and splints10. Joint stiffness may occur in the long term, but this has not been specifically studied in patients treated by modern operative techniques. It is possible that articular cartilage injury within the knee or ankle can occur at the time of tibial shaft fracture that may contribute to degenerative joint pathology and late stiffness.

Knee and ankle discomfort are common long term complaints" . At a mean of 17 years; 47% patients were free of discomfort, 17% had both knee and ankle discomfort, 26% had knee discomfort alone and 10% had only ankle discomfort. The level of discomfort in the majority did not affect their ability to work. The presence of long-term discomfort in the ankle was related to the severity of the initial injury, suggesting a degenerative process. Women were more likely to have ankle pain in this series, and this may be due to the women being much older than the men at the time of fracture, with the higher likelihood of pre-existing degenerative change in the joint. Vallier et al found that joint pain did not affect function in the majority of patients with a tibial shaft fracture. Tibial nails inserted through the patella tendon are associated with higher rates of anterior knee pain than nails inserted without disruption to the tendon. Removal of metalwork does not always resolve knee discomfort".

Post-phlebitic syndrome

Post-phlebitic syndrome of the lower limb and venous ulceration can occur, particularly in older patients, after tibial shaft fracture. This phenomenon may not present clinically for up to 10 years following injury and therefore Aitken et al highlighted the potential medico­ legal implications of early settlement of cases with regard to the onset of these symptoms.

Return to work

In a series of 1502 patients, of the patients alive for review;  74.6% were able to return to their pre-injury employment. Of the remaining 25.4%; 17.3% were unemployed at the time of injury, 2.3 % changed to a less physically demanding job , 0.5% took early retirement and 7% reported they were unable to return to work due to continuing disability. Younger patients had a higher likelihood of return to work, and earlier return to work. Increased age and presence of a grade II open fracture was associated with a reduced likelihood of returning to work at all.

Mortality

Crude mortality at 17 years following a tibial shaft fracture is 37.5%. Mortality in the 12 months following fracture is high in the elderly. The one-year mortality in patients aged 65-69 is 6.5%, this rises to 21.6% in those aged 70-74 and 31.6% in those aged over 85 years at the time of injury. This mortality rate is similar to patients who sustain a hip fracture. 

Leela is Consultant Trauma & Orthopaedic Surgeon at The Royal Infirmary of Edinburgh , Honorary Senior Lecturer at The University of Edinburgh, NRS Career Clinician Scientist Fellow. Her clinical practice, translational and clinical research interests are in the area of degenerative joint disease of the knee from cartilage repair to joint replacement, and optimising outcome for injured patients.

Author: Leela Biant, Consultant Trauma and Orthopaedic Surgeon, Royal Infirmary of Edinburgh

This article was first published in the May 2014 edition of the JTO.