Validity and Reliability of Intraoperative Radiographs to Assess Leg Length During Total Hip Arthroplasty: Correlation and Reproducibility of Anatomic Distances.
Leg length discrepancy after total hip arthroplasty is a frequent complication. The aim of this study was to assess the validity (correlation) and reproducibility (inter-rater agreement) of various intraoperative hip radiographs measures to estimate leg length.



Patients were included if they were aged 15 years or older; were eligible for a total hip arthroplasty, and were operated in lateral recumbent. An intraoperative hip radiograph was performed with the definitive implants in place. At 6 weeks postoperatively, anteroposterior pelvis radiograph was taken. We used 3 measures to assess leg length: the height from the ischial tuberosity to the lesser trochanter (LTI), the height from the center of femoral head to the greater trochanter (GTC), and to the inferior teardrop (TC).



The study group consisted of 71 hips with an average age of 69 years (range, 24-92 years). The correlation was 0.545 (95% CI: 0.35-0.69) for GTC, 0.75 (95% CI: 0.61-0.84) for TC, and 0.70 (95% CI: 0.56-0.80) for LTI. Intraoperative and postoperative measures were statistically different for GTC (<0.0001) and TC (<0.0001), and not significant for LTI (P = .06). Reproducibility of these measures were excellent with intraclass correlation coefficients of 0.977, 0.814, and 0.983 for the GTC, TC, and LTI, respectively.



None of the parameters used to assess leg-length based on an intraoperative radiograph showed good correlation with the postoperative radiograph.
Service orthopédie et traumatologie, Hôpital Cochin, APHP, Paris, France; Université Paris Descartes, Paris, France INSERM U1153, Paris, France.
Olivier
O
Herisson
Service orthopédie et traumatologie, Hôpital Cochin, APHP, Paris, France; Université Paris Descartes, Paris, France INSERM U1153, Paris, France.
Arnaud
A
Felden
Service orthopédie et traumatologie, Hôpital Cochin, APHP, Paris, France; Université Paris Descartes, Paris, France INSERM U1153, Paris, France.
Moussa
M
Hamadouche
Service orthopédie et traumatologie, Hôpital Cochin, APHP, Paris, France; Université Paris Descartes, Paris, France INSERM U1153, Paris, France.
Philippe
P
Anract
Service orthopédie et traumatologie, Hôpital Cochin, APHP, Paris, France; Université Paris Descartes, Paris, France INSERM U1153, Paris, France.
David J
DJ
Biau
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000601:surgery; D005270:Femur Head / Q000601:surgery; D006621:Hip Joint / Q000601:surgery; D006801:Humans; D007430:Intraoperative Care; D007870:Leg Length Inequality / Q000000981:diagnostic imaging* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care; D011183:Postoperative Complications / Q000000981:diagnostic imaging* / Q000209:etiology; D011446:Prospective Studies; D011859:Radiography / Q000379:methods*; D015203:Reproducibility of Results; D055815:Young Adult
hip arthroplasty complication; intraoperative radiograph; lateral recumbent; leg length discrepancy; pelvic orientation; total hip arthroplasty