Are internal lengthening devices effective and associated with less complications compared to other lengthening devices? A systematic review and meta-analysis

Abstract

Internal lengthening devices became more popular than external fixators. This was attributed to their effectiveness and lower complication rates. However, this is an assumption that is not on the basis of solid scientific evidence. Therefore, this study systematically reviewed the quality and strength of evidence supporting femoral internal lengthening devices' effectiveness and their associated complications. Six electronic databases (PubMed, Cochrane, Sage, Embase, Web of Science and Scopus) were searched from inception until 20 June 2020. Further, all included articles' bibliographies were searched manually. After screening of retrieved articles, five studies were eligible for qualitative and quantitative synthesis. Studies were assessed by two independent assessors using a modified 'assessment of the methodological quality both of randomized and nonrandomized studies of health care interventions'. Further, meta-analysis was conducted to compare the procedure's effectiveness, in terms of healing index and major complications incidence. Our findings showed internal validity as the major source of bias whereas external validity was the least. For healing index, there is limited evidence that internal lengthening devices lower healing index by 0.45 months/ cm (95% CI, −0.62 to −0.28; P < 0.01) compared to LON/ external fixators. The incidence of major complications, that were directly related to the procedures, did not differ between internal lengthening devices and other fixators (risk ratio=0.97; 95% CI, 0.39-2.44; P < 0.95). This review provides evidence that supports lower healing index and similar complications associated with internal lengthening devices compared to other procedures of femoral lengthening. However, the evidence is very limited to draw a solid conclusion.

What’s New in Limb Lengthening and Deformity Correction

“…Rehan Youssef et al performed a meta-analysis of the literature on internal lengthening devices used in femoral lengthening. The authors found evidence that supports a lower healing index and similar major complication rate associated with internal lengthening devices compared with other procedures for femoral lengthening 38 .…”

Limb reconstruction in a resource-limited environment

“…All internal bone transport of long bones can be achieved with designated transport nails or Plate-or Fibula-Assisted Bone Segment Transport (PABST/FAST) [37][38][39][40][41]. The complication rate and patient comfort may favor these internal solutions compared with external fixation [7,42]. However, the cost-effectiveness and clinical outcome has not been studied in detail using a robust scientific methodology.…”

“…In HICs, computer-assisted external fixation and intramedullary lengthening nails are marketed as a breakthrough technology in limb reconstruction. However, studies report that in-depth experience with more traditional circular frames can avoid the expenses of computer-assisted external fixators and achieve very acceptable clinical outcomes for challenging cases [ 4 , 7 ].…”

“…Limb lengthening and reconstruction surgery, including the management of congenital and acquired deformities, complex acute fractures, pseudarthrosis, and osteomyelitis, have advanced substantially in the last two decades [1,2]. Leaps in technological advances have introduced computer-aided deformity correction software and hexapod external fixators, intramedullary lengthening and bone transport nails, patientspecific additive manufacturing solutions, and a whole host of biological options to the field of limb reconstruction [3][4][5][6][7]. These technologies, however, are relatively expensive and not universally available, especially in resource-limited low-and middle-income countries (LMICs).…”

Letter to the Editor: What Are the Potential Benefits and Risks of Using Magnetically Driven Antegrade Intramedullary Lengthening Nails for Femoral Lengthening to Treat Leg Length Discrepancy?

“…Although lengthening nails are marketed as a breakthrough technology in limb reconstruction that avoid the complications associated with external fixation, there is no substantial evidence to confirm this claim. A systematic review my group performed found slight advantages in terms of healing time and no differences in complications between this approach and more conventional approaches (lengthening over a nail or external fixation), and the quality of the evidence we found was low [3].…”