Tag Archive | external fixation

Micromotion Followed by Rigid Fixation Boosts Fracture Healing

Mechanical factors undoubtedly play a role in the rate and quality of fracture healing. For example, the seminal work on fracture strain by the late Stephan Perren, MD helped us understand that the larger the overall fracture area, the lower the fracture strain—and that less strain encourages fracture union.

But with the variety of fracture planes and orientations, different energies imparted to produce the fracture, and multiple patient factors such as bone density, the best approaches by which to positively influence fracture-healing mechanics are still being investigated. We do know that motion mechanics come into play for nonsurgically stabilized fractures in our patients.

In the February 3, 2021 issue of The Journal, Glatt et al. provide more data on the role of micromotion in fracture healing. The authors created a 2-mm transverse tibial osteotomy in 18 goats and then used an external fixator to achieve static, rigid fixation in 6 of the osteotomized tibiae. Six other tibiae were treated with a fixator that allowed 2 mm of controlled axial micromotion for the 8-week duration of the experiment. (This so-called dynamization technique was championed more than 30 years ago by Fred Behrens, MD, who established that inducing micromotion helps stimulate maturation of fracture callus.) The remaining 6 tibiae were initially treated with dynamization, followed by rigid fixation during weeks 4 through 8—a technique known as reverse dynamization. The experimental groups simulated 3 different versions of cast or brace immobilization without surgery.

Using radiographs, micro-CT data, and torsion testing, the investigators found that, after 8 weeks, bones in the reverse-dynamization group were significantly stronger and showed more characteristics of intact, contralateral tibiae than the treated bones in the other 2 groups. I agree with the authors’ conclusion that their results “may have important consequences regarding our understanding of the optimum fixation stability necessary to maximize the regenerative capacity of bone-healing clinically.” With this experiment, Glatt et al. have added another important piece to the puzzle that Drs. Perren and Behrens started solving many years ago.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

High-Level Clinical Research in Developing Countries? Yes!

Generally speaking, orthopaedic surgeons in low-resourced environments deliver the best care for their patients with skill, creativity, and passion. These surgeons are accustomed to scrambling for implants and other tools and to working around limited access to operating theaters and anesthesia services. Their everyday struggles usually leave little energy or time to even think about clinical research.

However, in the May 20, 2020 issue of The Journal, Haonga and colleagues prove that, with a “little help from their friends,” it is possible to conduct Level I research while treating patients in a resource-limited setting. They enrolled and followed 221 patients with open tibial fractures (mostly males in their 30s injured in a road-traffic collision) and randomized them to treatment with either uniplanar external fixation or intramedullary (IM) nailing. The nails were supplied by SIGN Fracture Care International, a not-for-profit humanitarian organization that provides specially designed IM nails that can be used without image intensification to hospitals in developing countries around the world. (See related OrthoBuzz post.)

The research was done in Dar es Salaam, Tanzania, in collaboration with trauma surgeons and epidemiologists from the University of California San Francisco, which has a long-standing relationship with Tanzania’s Muhimbili National Hospital. At the 1-year follow-up, there were no significant between-group differences in primary-outcome events—death or reoperation due to deep infection, nonunion, or malalignment. IM nailing was associated with a lower risk of coronal or sagittal malalignment, and quality-of-life (QoL) scores favored IM nailing at 6 weeks, but QoL differences dissipated by 1 year.

Just as important as the clinical findings, these investigators proved that it is possible to do high-level research in centers with high patient volume and limited resources. Future patients will benefit because the clinicians now have better information to share regarding expectations for functional recovery and risk of infection. Physicians and other healthcare professionals benefit because data like this help improve their analytical skills and become more discerning appraisers of the published literature. With strong internal physician leadership and a little outside support, Haonga et al. have convinced us that prospective—and even randomized—research is possible in these special places.

Finally, SIGN deserves our support as a true champion of orthopaedic surgeons working in under-resourced environments. In addition to providing education and implants, SIGN surgeons are required to report their cases through the SIGN Surgical Database—which encourages the research mindset and helps SIGN surgeons improve tools and techniques for better patient outcomes.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Delaying Knee Replacement: Driven to Distraction?

This post comes from Fred Nelson, MD, an orthopaedic surgeon in the Department of Orthopedics at Henry Ford Hospital and a clinical associate professor at Wayne State Medical School. Some of Dr. Nelson’s tips go out weekly to more than 3,000 members of the Orthopaedic Research Society (ORS), and all are distributed to more than 30 orthopaedic residency programs. Those not sent to the ORS are periodically reposted in OrthoBuzz with the permission of Dr. Nelson.

Some symptomatic patients with knee osteoarthritis (OA) present relatively early in the radiographic disease process, while others present after serious articular cartilage loss has occurred. In either case, young knee OA patients are often looking for ways to get relief while postponing a total knee arthroplasty (TKA).

One such recently introduced alternative is knee joint distraction (KJD), a joint-preserving surgery used for bicompartmental tibiofemoral knee osteoarthritis or unilateral OA with limited malalignment. Significant long-term clinical benefit as well as durable cartilage tissue repair have been reported in an open prospective study with 5 years of follow-up.1 A more recent study of distraction2 presents 2-year follow-up results of a 2-pronged trial that measured patient-reported outcomes, joint-space width (JSW), and systemic changes in biomarkers for collagen type-II synthesis and breakdown.

In one arm, end-stage knee OA patients who were candidates for TKA were randomized to KJD (n=20) or TKA (n=40). In the second arm, earlier-stage patients with medial compartment OA and a varus angle <10° were randomized to KJD (n=23) or high tibial osteotomy (HTO; n=46). In the distraction patients, the knee was distracted 5 mm for 6 weeks using external fixators with built-in springs, placed laterally and medially, and weight-bearing was encouraged. WOMAC scores and VAS pain scores were assessed at baseline and at 3, 6, 12, 18, and 24 months.

At 24 months, researchers found no significant differences between the KJD and HTO groups in that part of the trial. In the KJD/TKA arm, there was no difference in WOMAC scores between the two groups, but VAS scores were lower in the TKA group. The improvement in mean joint space width seen at one year in the KJD group of the KJD/TKA arm decreased by two years, though the values were still improved compared to baseline. However, the joint space width improvement seen at 1 year for both groups in the KJD/HTO arm persisted for two years. For all KJD patients, the ratio of biomarkers of synthesis over breakdown of collagen type-II was significantly decreased at 3 months but reversed to an increase between 9 and 24 months.

It is hard to believe that 6 weeks of joint distraction could trigger a process that yields such positive and long-lasting results. While much more research with longer follow-up is needed, KJD may prove particularly useful in younger knee OA patients trying to delay joint replacement.

References

  1. van der Woude, JAD, Wiegant, K, van Roermund, PM, Intema, F, Custers, RJH, Eckstein, F. Five-year follow-up of knee joint distraction: clinical benefit and cartilaginous tissue repair in an open uncontrolled prospective study. Cartilage. 2017;8:263-71.
  2. Jansen MP, Besselink NJ, van Heerwaarden RJ, Roel J.H. Custers1, Jan-Ton A.D. Van der Woude J-TAD, Wiegant K, Spruijt S, Emans PJ, van Roermund PM, Mastbergen SC, Lafeber FP. Knee joint distraction compared with high tibial osteotomy and total knee arthroplasty: two-year clinical, structural, and biomarker outcomes. ORS 2019 Annual Meeting Paper No. 0026 (Cartilage. 2019 Feb 13:1947603519828432. doi: 10.1177/1947603519828432. [Epub ahead of print])

What’s New in Limb Lengthening/Deformity Correction: Level I and II Studies

Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Here is a summary of selected findings from Level I and II studies cited in the August 19, 2015 Specialty Update on limb lengthening and deformity correction:

Pediatric Disorders and Trauma

–A modified guided-growth technique for insertion of tension-band plates decreased operative time, radiation exposure, and incision size.1

–Two meta-analyses concluded that, although oral or intravenous bisphosphonates in children with osteogenesis imperfecta increased bone mineral density, evidence of reduction in fracture rates was inconclusive.2, 3

–A systematic review of 40 studies on surgical management of posttraumatic cubitus varus in children noted an overall complication rate of 14.5%, with no single technique being substantially safer or more effective.4

 Lower-Limb Trauma/Reconstruction in Adults

–A prospective randomized study on the surgical treatment of complex knee dislocations with ligament reconstruction found a significantly lower risk of delayed ligament failure with adjunctive hinged external fixation compared with a hinged knee brace.

–A prospective randomized study comparing biplanar external fixation with reamed interlocking intramedullary nailing for treating open tibial shaft fractures found similar healing rates and functional outcomes one year postoperatively.5

–Patients with extra-articular distal tibial fractures treated with circular external fixators had earlier weight-bearing and superior function compared with those managed with plate fixation.6

–A randomized controlled trial of patients with medial compartment knee osteoarthritis reported similar radiographic outcomes six years postoperatively among those who had opening-wedge high tibial osteotomy compared with those who had undergone closing-wedge high tibial osteotomy. The closing-wedge group had fewer complications but greater prevalence of conversion to total knee arthroplasty.

Foot and Ankle Reconstruction

–A multicenter prospective study comparing ankle arthroplasty with ankle arthrodesis noted similar patient-reported outcomes, although revision rates and major complications were higher following ankle replacement.

Managing Postoperative Complications

–A comparative study noted a lower prevalence of pin-site infections with the use of chlorhexidine (9.2%) compared with povidone-iodine (27.9%) following external fixation.7

–A randomized study revealed a 27% reduction in external fixation time with the use of low-intensity pulsed ultrasound for tibial osteoplasty.8

–A randomized trial in patients undergoing bilateral tibial lengthening showed no improvement in postoperative pain or ankle-joint mobility following botulinum toxin A injection in the calf muscle.9

New Tools and Techniques

–In a matched-pair study, patients undergoing femoral lengthening using a motorized intramedullary nail showed better consolidation indices, better knee mobility, and decreased complication rates compared with conventional external fixation.10

References

  1. MasquijoJJ, Lanfranchi L, Torres-Gomez A, Allende V. Guided growth with the tension band plate construct: a prospective comparison of 2 methods of implant placement. J Pediatr Orthop. 2015 Apr-May;35(3):e20
  2. Dwan K, Phillipi CA, Steiner RD, Basel D. Bisphosphonate therapy for osteogenesis imperfecta. Cochrane Database Syst Rev. 2014;7:CD005088. Epub 2014 Jul 23
  3. Hald JD, Evangelou E, Langdahl BL, Ralston SH. Bisphosphonates for the prevention of fractures in osteogenesis imperfecta: meta-analysis of placebo-controlled trials. J Bone Miner Res.2014 Nov 18
  4. Solfelt DA, Hill BW, Anderson CP, Cole PA. Supracondylar osteotomy for the treatment of cubitus varus in children: a systematic review. Bone Joint J. 2014May;96-B(5):691-700
  5. Rodrigues FL, de Abreu LC, Valenti VE, Valente AL, da Costa Pereira Cestari R,Pohl PH, Rodrigues LM. Bone tissue repair in patients with open diaphyseal tibial fracture treated with biplanar external fixation or reamed locked intramedullary nailing. Injury. 2014 Nov;45(Suppl 5):S32-5
  6. Fadel M, Ahmed MA, Al-Dars AM, Maabed MA, Shawki H. Ilizarov external fixation versus plate osteosynthesis in the management of extra-articular fractures of the distal tibia. Int Orthop. 2015 Mar;39(3):513-9. Epub 2014 Dec 5
  7. Cam R, Demir Korkmaz F, Oner Şavk S. Effects of two different solutions used in pin site care on the development of infection. Acta Orthop Traumatol Turc.2014;48(1):80-5
  8. Salem KH, Schmelz A. Low-intensity pulsed ultrasound shortens the treatment time in tibial distraction osteogenesis. Int Orthop. 2014 Jul;38(7):1477-82. Epub 2014 Jan 7
  9. Lee DH, Ryu KJ, Shin DE, Kim HW. Botulinum toxin A does not decrease calf pain or improve ROM during limb lengthening: a randomized trial. Clin Orthop Relat Res.2014 Dec;472(12):3835-41
  10. Horn J, Grimsrud Ø, Dagsgard AH, Huhnstock S, Steen H. Femoral lengthening with a motorized intramedullary nail. Acta Orthop. 2015 Apr;86(2):248-56. Epub 2014 Sep 5