gms | German Medical Science

Objectives: Trochanteric fractures are one of the most frequent fractures, affecting especially geriatric patients. Despite well-established treatment standards, complication rates remain high, not only due to general medical reasons, but also due to implant-related reasons. This retrospective study was set up to compare the complication rates of two different cephalomedullary nails (CMN) of the same manufacturer.

Methods: Patient identification was done through a keyword search of the electronic patient file database of a single institution, using the ICD-10 codes S72.XX between January 2017 and July 2021. The identified cases were screened manually for the use of CMN. The study population was then separated in two groups using either the PFN-A or the TFN-A. Outcome parameters were all kind of reoperations, conversion to total hip arthroplasty (THA), and patient survival. Reoperations were differentiated as minor reoperation (any reoperation without exchange of any components), minor revision (exchange of cervical blade/screw only, definitive implant removal) or major revision (reosteosynthesis, conversion to THA). Furthermore, patient demographics, implant specifications and reasons for reoperation were collected. Fractures were classified according to the AO/ASIF classification. Quality of reduction and fixation were classified using the Baumgartner criteria, the Cleveland zones and the tip-apex-distance.

Results and conclusion: In total 475 cases of CMN were detected, in 248 cases the PFN-A and in 244 the TFN-A was used. There were no differences between both groups regarding demographics, quality of reduction and fixation, and AO/ASIF classification. Reoperation and revision occurred mainly early, within less than a year. Overall, 75 (15,24%) reoperations were recorded with 33 (13.31%) in the PFN-A group and 42 (17.21%) in the TFN-A group. Higher rates of major revisions (2.02% vs. 7.38%) and implant failure were detected for the TFN-A group. Concerning nail specifications, the standard caput-collum-diaphyseal (CCD) was 130° in the TFN-A, whereas it was 125° in the PFN-A. The TFN-A was made of titanium, whereas the PFN-A was made of stainless steel.

Discussion: Reoperations, respectively conversion to THA were necessary mainly early after internal fixation of trochanteric fractures, occurring mainly during the first few months. In this cohort, the newer TFN-A seems to have a higher rate of major complications, such as nail breakage and cut-through/out/in, compared to the older PFN-A, despite some protective factors, such as a higher CCD and composition of material with a higher fatigue endurance. This study shows that a systematic follow up of implants is necessary to assess their performance, as all implants may not be considered equal.