Characteristics of intramedullary nail breakage in pertrochanteric femur fractures: a summary of 70 cases

Abstract

Objective To reveal noteworthy characteristics of intramedullary (IM) nail breakage in pertrochanteric femur fractures. Materials and methods The data from 6 patients with IM nail breakage in our hospital between August 2008 and May 2018 were reviewed retrospectively. With an additional 64 cases reported in articles in the PubMed database prior to October 2019, a total of 70 cases were reviewed and analysed; epidemiological patient data and data on the initial trauma, fracture type, nail selected for the original surgery, time from surgery to breakage, mechanism and location of breakage, status of fracture healing, salvage treatment and prognosis were assessed. Results Seventy patients with pertrochanteric fractures, including 2 stable fractures and 68 unstable fractures, experienced IM nail breakage at a mean of 9.4 months after the initial surgery. Among them, 9 (12.9%) occurred within 3 months, 23 (32.9%) between 3 and 6 months and 38 (54.3%) after 6 months. The mean age was 72.3 years, and 16 (22.9%) patients were younger than 65 years old. When nail breakage occurred, 66 fractures (94.3%) exhibited delayed union/non-union. Self-dynamisation was found in 12 cases (17.1%). The salvage procedures included 4 partial/total implant removal procedures, 17 hemi/total hip arthroplasty procedures, 3 conservative treatment procedures, and 46 revised osteosyntheses, of which 7 cases (15.2%) sustained secondary implant failure. No significant differences were found between the failure rates of IM nails and extramedullary(EM) devices (odds ratio [OR], 3.429; 95% confidence interval [CI], 0.632–18.877; p = 0.330). Conclusion IM nail breakage is a rare complication lack of time regularity and mostly occurs in unstable pertrochanteric fractures in the presence of delayed union/non-union. Osteosynthesis revision can be conduct by a new IM nail or EM device but considerable secondary failure rate is noteworthy. Self-dynamisation may be a warning sign of nail breakage.

Tips and tricks to avoid implant failure in proximal femur fractures treated with cephalomedullary nails: a review of the literature

“…In these cases, the largest possible diameter nail should be utilized, and the patient should be carefully followed, as the implant cannot be assumed to outlive the patient [10,14] . Special emphasis regarding failure of implants has been associated with reverse oblique and especially subtrochanteric fractures [10,15,16] . These unstable fracture types are definite indications for the use of a cephalomedullary nail over an extramedullary implant.…”

“…One of the main goals of intramedullary nailing of the proximal femur is to achieve healing in an anatomical position. Implant breakage before healing has been associated with malreduction or improper implant positioning in unstable intertrochanteric fractures and subtrochanteric fractures [10,15] . In intertrochanteric fractures, anatomical reduction is pivotal before reaming to allow proper nail placement.…”

“…In the setting of comminution or poor reduction, there may be lack of cortical contact, large fracture gap, and excessive interfragmentary motion leading to high strain preventing bone healing according to Perren's theory [29] . Distal locking screw breakage has also been reported to commonly occur before implant failure at the nail itself [10,15,28] . This may be a symptom of nonunion and excessive interfragmentary motion, and a warning sign for impending failure of the implant itself, rather than a cause.…”

Proximal Femoral Nail Mechanical Failure: A Case Report and Biomechanical Study

“…A fracture union is a race between the bony union and implant failure [ 11 ]. Several mechanisms leading to implant failure have been already described in the literature.…”

“…These mechanisms can be implanted, patient or surgeon dependent, or combinations of the above. Many authors suggest that the initial fracture pattern (unstable, subtrochanteric extension, pathological fracture), poor fracture reduction during index surgery, and delayed union/nonunion are risk factors for implant failure [ 6 , 10 , 11 , 14 , 15 ].…”