Intrapelvic Migration of the Lag Screw in Intramedullary Nailing

Abstract

Internal fixation with intramedullary devices has gained popularity for the treatment of intertrochanteric femoral fractures, which are common injuries in the elderly. The most common complications are lag screw cut out from the femoral head and femoral fracture at the distal tip of the nail. We report here a rare complication of postoperative lag screw migration into the pelvis with no trauma. The patient was subsequently treated with lag screw removal and revision surgery with total hip arthroplasty. This case demonstrated that optimal fracture reduction and positioning of the lag screw are the most important surgical steps for decreasing the risk of medial migration of the lag screw. Furthermore, to prevent complications, careful attention should be paid to subsequent steps such as precise insertion of the set screw.

Complications After Hip Nailing for Fractures

“…[33][34][35] Medial migration into the pelvis of the femoral head lag screw has been related to suboptimal femoral head lag screw positioning. [36][37][38][39][40][41] This phenomenon has been associated mostly with proximal femur nails (PFNs; Synthes, Paoli, Pennsylvania), but it was recently demonstrated in a study of 5 different nails (TFN, PFN, and PFNA; Synthes; and Gamma-3; Stryker; and IMHS; Smith & Nephew) in a biomechanical model of an unstable pertrochanteric fracture. The nails were examined to an endpoint of 9 mm of medial migration on completion of 5000 loading cycles.…”

“…[33][34][35] Medial migration into the pelvis of the femoral head lag screw, similar to the reverse z-effect, may occur with hip nails comprising a single femoral head lag screw. [36][37][38][39][40][41] Sporadic cases of this complication have been reported in the setting of suboptimal femoral head lag screw positioning. [36][37][38][39][40][41] Intrapelvic complications from medial migration of the femoral head lag screw may be significant, including sigmoid perforation, retroperitoneal abscess formation, and neurovascular injuries.…”

Migração intrapélvica do parafuso cefálico da haste intramedular longa para fêmur proximal: Relato de caso*

“…Heineman et al 5 described the case of an 83-year-old woman who, after three weeks of fixation, presented pin migration to the pelvic region, and was submitted to a twostage treatment: initially, removal of the implants, and later, cementless THA. Takasago et al 6 presented a case of a 63-year-old woman with medial migration, 6 weeks after surgery. They also performed the review in two stages, with implant removal and subsequent THA.…”

“…Other possible causes also reported in the literature are cephalic screw misplacement, improper insertion of the anti-rotation locking device, increased TAD, femoral head damage by repetitive milling, and avascular necrosis of the femoral head. 6 Medial migration of the cephalic screw is an uncommon complication in the orthopedic literature, without description of reported cases associating it with the long cephalomedullary nail or with the treatment with proximal femur locking plate.…”

Fracturas de cadera de trazo basicervical con inestabilidad rotacional: estudio retrospectivo de la eficacia de dos sistemas de incremento de la estabilidad mecánica del implante

“…• Errores técnicos: exceso del tip apex distance (225,227), colocación excesivamente subcondral de la punta del tornillo, bloqueo estático de la espiral que impide el deslizamiento (232) o reducción insuficiente de la fractura (225). Las tasas de fracaso del implante de los estudios clásicos ha oscilado entre 5% y 16.5% con los sistemas de tornillo deslizante (207), siendo el cut out la complicación más frecuente (75%-84%) del total de fracasos (170,207), pero actualmente la incidencia ha descendido a un 2-3% (0.9-6%) para el sistema PFNA® (146,147,(149)(150)(151)154).…”