Session III - Hip / Femur

Fri., 10/11/13 Hip/Femur, PAPER #52, 11:01 am OTA 2013

Femoral Neck Shortening Impairs Gait Pattern and Muscle Strength After Internal Fixation of a Femoral Neck Fracture

Stephanie M. Zielinski, MD1; Noël L.W. Keijsers2; Stephan F.E. Praet3; Martin J. Heetveld4;
Mohit Bhandari, MD, PhD, FRCSC5; Jean Pierre Wilssens6; Peter Patka7;
Esther M.M. Van Lieshout1; on behalf of the FAITH trial investigators;
1 Department of Surgery-Traumatology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands;
2Department of Research, Development and Education, Sint Maartenskliniek,
Nijmegen, The Netherlands;
3Department of Rehabilitation Medicine & Physical Therapy, Erasmus MC,
University Medical Center Rotterdam, Rotterdam, The Netherlands;
4Department of Surgery, Kennemer Gasthuis, Haarlem, The Netherlands;
5Department of Clinical Epidemiology and Biostatistics, McMaster University,
Hamilton, Ontario, Canada;
6RSscan International, Olen, Belgium;
7Department of Accident & Emergency Medicine, Erasmus MC, University Medical Center
Rotterdam, Rotterdam, The Netherlands

Purpose: Knowledge of long-term physical limitations in patients after internal fixation of a femoral neck fracture is limited. The aim of this study was to assess femoral neck shortening and its consequences on gait pattern and muscle strength in femoral neck fracture patients treated with internal fixation.

Methods: Patients were selected from a multicenter randomized controlled trial, in which femoral neck fracture patients aged ≥50 years, who were ambulatory and not demented prefracture, and treated with internal fixation were studied. Patients were included at least 1 year after internal fixation. Exclusion criteria were (1) revision surgery, (2) unable to walk, (3) other limb abnormality expected to influence gait pattern, (4) previous surgery of the contralateral hip, and (5) radiographs inadequate for measurements. Patient characteristics, SF-12 (Short-Form 12), and WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index  scores were collected. Femoral neck shortening was measured radiologically and gait parameters were measured using plantar pressure measurement. Maximum isometric forces of the hip muscles were assessed using handheld dynamometry. Differences between the fractured and the contralateral leg were calculated. Patients were divided into three subgroups of patients with increasing level of femoral neck shortening. Univariate and multivariable analyses were performed to determine risk factors for femoral neck shortening and effects of femoral neck shortening.

Results: 76 patients (median age 68 years) were included. The median femoral neck shortening was 1.1 cm. A heel lift to compensate for this shortening was used by 30% of the patients. Patient self-reported functioning was good (median WOMAC score 86.5). Overall, subtle changes in gait pattern as well as a reduced gait velocity (median 1.1 m/sec) and reduced abductor muscle strength (median –20 N) were observed. Age, weight, and Pauwels classification were risk factors for increased femoral neck shortening. Femoral neck shortening decreased gait velocity and seemed to impair gait symmetry and physical functioning.

Conclusion: Internal fixation of femoral neck fractures resulted in permanent physical limitations, such as femoral neck shortening, subtle changes in gait pattern, reduced gait velocity, and reduced abductor muscle strength. The relatively young and healthy patients in our study seem capable of compensating. Therefore, attention should be paid to femoral neck shortening and proper correction with a heel lift, as inadequate correction may cause physical complaints and influence outcome.

Alphabetical Disclosure Listing

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.