Tag Archive | 3-D printing

What’s New in Limb Lengthening and Deformity Correction 2019

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.

Congenital Pseudarthrosis
–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

3-Dimensional Printing
–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

References

  1. 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.
  2. 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.
  3. 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.
  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]

3-D Printing: An Orthopaedic Update

OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Chad Krueger, MD, in response to an article at MedCityNews.com that announced a 3-D printing alliance between Johnson & Johnson and HP.

There’s much focus lately on healthcare concepts in which each patient’s treatment is tailored to his or her specific condition, anatomy, and, in some cases, genetic make-up. Within that realm of so-called “personalized medicine,” surgeons are becoming increasingly interested in tailoring procedures and implants to specific individuals. The MedCity News article discusses how Johnson & Johnson has partnered with HP to further develop 3-D printing capabilities, with a goal of giving surgeons more patient-specific options.

3-D_Scaffold.pngOne of the particular devices J & J is pursuing involves 3-D-printed bone-graft cages that form an osteoconductive scaffold for critical-size bone defects. Developing such a scaffold could go a long way toward promoting quicker and better outcomes in cases for which current techniques are very technically demanding.  Three-D printing may eventually deliver a patient-customized scaffold that promotes bone healing, inhibits microbiologic activity, provides biomechanical strength, and is easier for surgeons to use.

The article also discusses how customized 3-D-printed implants have already been used at some facilities for “unique” patients, such as those whose challenging revision surgery would normally require substantial “trial and error” intraoperatively to properly fit implants.  This printing technology can also facilitate production of customized cutting jigs, retractors, and other tools specific to individual patients. Companies are even using 3-D technology to develop casts, braces, and other interventions used in the nonoperative treatment of orthopaedic conditions (see related OrthoBuzz post).

Additionally, 3-D printing can be used in the preoperative period to provide surgeons with a better understanding of the bony anatomy they will encounter during a case. This type of preoperative templating is already being used on complex heterotopic ossification removals, spinal deformity corrections, and other difficult operations.  These 3-D-printed models can also be used to educate patients and increase their understanding of the planned procedure.

Despite all the promise surrounding 3-D printing, hurdles are abundant. For example, an entirely new regulatory framework will need to be developed to ensure the quality and safety of these products. Even if the capabilities of this technology increase and the costs decrease, we must remember the many other exciting device technologies that elicited similar early excitement but were found to be less useful than anticipated.

Nevertheless, companies such as Stryker are already spending hundreds of millions of dollars to build facilities devoted to industrial 3-D printing, and they will be looking for a return on that investment. So, despite the exhilaration and promise that come with new technologies, it is important to recognize their potential limitations—and to have open discussions with patients about all that remains unknown in regard to their use.

Chad Krueger, MD is a military orthopaedic surgeon at Womack Army Medical Center in Fort Bragg, NC.

Click here to read a JBJS Reviews article about the surgeon’s role in introducing new orthopaedic technologies.