OTSR - 2026-07-10 - Journal Article
Impact of Nail-to-Medullary Canal Ratio on Proximal Femoral Shortening in Osteoporotic Pertrochanteric Fractures".
Yüksel S, Barça F, Demir EB, Atlı OY, Ersan Ö
Topics
Key Takeaway
A higher nail-to-medullary canal ratio (NMR) independently reduces proximal femoral shortening after Gamma3 nailing of osteoporotic pertrochanteric fractures, with mean PFS of 5.02 mm and severe shortening (≥10 mm) occurring in 17.2% of patients.
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Summary
This study asked whether NMR influences postoperative proximal femoral shortening in patients >60 years with OTA/AO 31A1–31A3 fractures treated with short Gamma3 nailing. PFS was quantified using 3-component vector analysis comparing the operative to contralateral hip; multivariable regression identified NMR, fracture instability (31A2–31A3), and poor reduction quality as independent predictors of greater shortening. The protective effect of higher NMR was confined to unstable fracture patterns and did not correlate with implant failure in 7 cases.
Key Limitation
Follow-up duration and timing of PFS measurement are not reported, precluding assessment of whether shortening progresses or stabilizes over time.
Original Abstract
BACKGROUND
Proximal femoral shortening (PFS) is a common but often under-recognized mechanical complication following proximal femoral nailing (PFN) for pertrochanteric fractures and may adversely affect hip biomechanics and functional outcomes. The objective of this study was to determine whether the nail-to-medullary canal ratio (NMR) influences postoperative PFS in patients with osteoporotic pertrochanteric fractures treated with PFN, and to identify risk factors associated with increased shortening.
HYPOTHESIS
We hypothesized that a higher nail-to-medullary canal ratio would be associated with reduced proximal femoral shortening after PFN in osteoporotic pertrochanteric fractures.
PATIENTS AND METHODS
This retrospective cohort study included 128 patients aged >60 years with osteoporotic pertrochanteric fractures (OTA/AO 31A1-31A3) treated using a short Gamma3 nail. PFS was quantified by comparing the operated hip with the contralateral uninjured side and calculating horizontal, vertical, and resultant z-vector components. Independent variables included age, sex, NMR, fracture type, and reduction quality. Multivariable regression analysis was used to identify predictors of PFS, with subgroup analyses performed for stable versus unstable fractures. Factors associated with reoperation were assessed using logistic regression.
RESULTS
The mean proximal femoral shortening was 5.02 ± 4.56 mm. Mild (5-10 mm) and severe (≥10 mm) shortening occurred in 18.8% and 17.2% of patients, respectively. In multivariable analysis, a higher NMR was independently associated with reduced PFS. Unstable fracture patterns (AO/OTA 31A2-31A3) and reduction quality other than good were associated with significantly greater shortening. Subgroup analysis demonstrated that the protective effect of a higher NMR was present in unstable fractures but not in stable fractures. Implant failure occurred in 7 patients and was not associated with NMR.
DISCUSSION
The use of nails that better fill the intramedullary canal may help prevent PFS, particularly in unstable pertrochanteric fractures. Fracture stability and reduction quality remained key determinants of postoperative shortening, whereas nail-to-medullary canal ratio was not related to implant failure.
LEVEL OF EVIDENCE
III; retrospective cohort study.