Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, Mark T. Dahl, MD, co-author of the August 21, 2019 “What’s New in Limb Lengthening and Deformity Correction,” selected the five most clinically compelling findings from among the 40 noteworthy studies summarized in the article.
–Authors of a retrospective study of 119 patients with Crawford type-II congenital pseudarthrosis of the tibia found a 69% union rate at maturity. They did not identify specific factors influencing rates of union or refracture, however.1
–The models created with this technology can help surgeons preoperatively assess specific anatomical geometries. Corona et al.2 used 3-D-printed titanium truss cages, along with the Masquelet technique, to treat massive infected posttraumatic defects.
Growth Prediction in Limb Lengthening
–A comparative evaluation of the predictive accuracy of 4 methods to correctly time epiphysiodesis in 77 patients found the multiplier method to be the least accurate. In a separate study of 863 epiphysiodeses, authors reported a 7% complication rate.3 The most common complication was incomplete arrest that resulted in angular deformities; half of those cases required reoperation.
Congenital Limb Deficiencies
–Over 16 years, Finnish children born with lower-limb deficiencies had 6 times the number of hospital admissions and 10 times the number of days in hospital per child, compared with children born without a limb deficiency.4
- Shah H, Joseph B, Nair BVS, Kotian DB, Choi IH, Richards BS, Johnston C, Madhuri V, Dobbs MB, Dahl M. What factors influence union and refracture of congenital pseudarthrosis of the tibia? A multicenter long-term study. J Pediatr Orthop. 2018 Jul;38(6):e332-7.
- Corona PS, Vicente M, Tetsworth K, Glatt V. Preliminary results using patient-specific 3D printed models to improve preoperative planning for correction of post-traumatic tibial deformities with circular frames. Injury. 2018 Sep;49(Suppl 2):S51-9.
- Makarov MR, Dunn SH, Singer DE, Rathjen KE, Ramo BA, Chukwunyerenwa CK, Birch JG. Complications associated with epiphysiodesis for management of leg length discrepancy. J Pediatr Orthop. 2018 Aug;38(7):370-4.
- Syvänen J, Helenius I, Koskimies-Virta E, Ritvanen A, Hurme S, Nietosvaara Y. Hospital admissions and surgical treatment of children with lower-limb deficiency in Finland. Scand J Surg. 2018 Nov 19:1457496918812233. [Epub ahead of print]
The article, “Guiding Femoral Rotational Growth in an Animal Model” by Arami, et al. is an intriguing variation on the common applications of guided growth in pediatric patients. Implants that bridge the physis to inhibit growth in a given anatomic location are widely used to correct angular deformity or leg-length differences in the growing child and to decrease the need for a more invasive corrective osteotomy.
At present, correction of rotational deformity in the pediatric femur or tibia requires a derotational osteotomy and commonly six weeks of casting postoperatively. This study in rabbits demonstrates the ability of implants to alter the rotational profile in the growing femur by bridging the physis in an oblique orientation, rather than in a vertical orientation used for angular deformity correction.
The authors have elegantly demonstrated histologically the swirling or bending appearance of the physeal columns in treated femora, while controls maintained the normal linear columnar appearance of the physis. This interesting and unique animal study lays the foundation for consideration of using oblique placement of physeal-bridging implants to guide rotational growth in skeletally immature patients, without the need for osteotomy.