Three Intraoperative Methods to Determine Limb-length Discrepancy in THA

http://www.healio.com/orthopedics/journals/ortho/%7B11443e87-3baa-4afb-8e77-8b2c2826321c%7D/three-intraoperative-methods-to-determine-limb-length-discrepancy-in-tha

FEATURE ARTICLE 

Three Intraoperative Methods to Determine Limb-length Discrepancy in THA

Ian S. Rice, MD; R. Lee Stowell, MD; Purab C. Viswanath, MD; Gary J. Cortina, MD

• Orthopedics
• May 2014 - Volume 37 · Issue 5: e488-e495
• DOI: 10.3928/01477447-20140430-61

Abstract

Dismetría ( LLD ) es una preocupación común para el cirujano y el paciente en el ámbito de la electiva de artroplastia total de cadera (THA ) . Hay una escasez de pruebas guiar a los cirujanos un método óptimo para la medición de LLD intraoperatoria y minimizar LLD postoperatorio. El objetivo principal de este estudio prospectivo, aleatorizado , doble ciego fue determinar cuál de 3 métodos intraoperatorias utilizadas en la institución de los autores fue mejor correlacionada con LLD radiográfica postoperatoria. Entre 2011 y 2012, 81 pacientes sometidos ya sea primaria ( 75 ) o la revisión ( 6 ) THA con un abordaje anterolateral (Watson -Jones ) fueron prospectivamente aleatorizados y recibió la medición intraoperatoria de LLD vía 1 de 3 métodos : Shuck secuestrador (AS) , tranosseous pines con pinza calibrada ( TP ) , o la rótula electrocardiograma derivaciones ( ECG) (PL ). Mediciones intraoperatorias de LLD se compararon con las mediciones postoperatorias clínicos y radiográficos de LLD , y se calcularon las diferencias absolutas y coeficientes de correlación para cada método. En general, la LLD media preoperatoria fue de 8,09 mm, y la media de LLD radiográfica fue después de la operación 4,20 mm . El método AS se asocia con la más alta correlación con LLD radiográfica postoperatoria (R = 0,360 , p < 0,05 ), mientras que los otros métodos tuvieron correlaciones moderadamente positivos , pero estadísticamente no significativos ( TP R = 0,275 , p> 0,05 ; PL R = 0.301 , p > 0,05 ) . El método AS mejor se correlaciona con LLD radiográfica postoperatoria entre las 3 técnicas, aunque todos los métodos se correlacionaron positivamente. Las mediciones clínicas de LLD correlacionan mal con las mediciones radiográficas y pueden ser de utilidad limitada .

Limb-length discrepancy (LLD) is a common concern for both surgeon and patient in the setting of elective total hip arthroplasty (THA). There is a paucity of evidence guiding surgeons to an optimal method for measuring intraoperative LLD and minimizing postoperative LLD. The primary objective of this prospective, randomized, double-blinded study was to determine which of 3 intraoperative methods used at the authors’ institution was best correlated to postoperative radiographic LLD. From 2011 to 2012, 81 patients undergoing either primary (75) or revision (6) THA with an anterolateral (Watson-Jones) approach were prospectively randomized and received intraoperative measurement of LLD via 1 of 3 methods: abductor shuck (AS), tranosseous pins with calibrated caliper (TP), or patella electrocardiogram (EKG) leads (PL). Intraoperative measurements of LLD were compared to clinical and radiographic postoperative measurements of LLD, and absolute differences and correlation coefficients were calculated for each method. Overall, the mean LLD preoperatively was 8.09 mm, and mean radiographic LLD postoperatively was 4.20 mm. The AS method was associated with the highest correlation to postoperative radiographic LLD (R=0.360; P<.05), whereas the other methods had mildly positive but statistically insignificant correlations (TP R=0.275; P>.05; PL R=0.301; P>.05). The AS method best correlates to postoperative radiographic LLD among the 3 techniques, although all methods were positively correlated. Clinical measurements of LLD correlate poorly with radiographic measurements and may be of limited utility.

The authors are from the Department of Orthopedic Surgery, UPMC Hamot Medical Center, Erie, Pennsylvania.

The authors have no relevant financial relationships to disclose.

Two calibrated sterilizable levels were donated to the hospital by Innomed, Inc prior to this study.

The authors thank Tim Cooney for assistance with statistical analysis and Joshua Rosenberg, MD, for radiographic measurements.

Correspondence should be addressed to: Ian S. Rice, MD, Department of Orthopedic Surgery, UPMC Hamot Medical Center, 201 State St, Erie, PA 16550 ( riceians@gmail.com).

Received: April 11, 2013

Accepted: November 08, 2013