A therapeutic Level II study by DiGiovanni et al. in the August 3, 2016 edition of The Journal of Bone & Joint Surgery examined the relationship between successful foot/ankle fusions and the amount of graft material used. The authors found that among 573 procedures in which graft material (either autograft or AUGMENT bone graft) occupied ≥50% of the cross-sectional fusion space at nine weeks, 81% were successfully fused at 24 weeks. However, among 101 procedures with <50% of the graft space filled, only 21% were successfully fused at 24 weeks.
The authors determined both graft-fill percentages at nine weeks and fusion success at 24 weeks using CT scans. The percentage of graft fill was estimated by mental summation of graft fill present in each individual CT slice of the joint, and joint fusion was determined by measuring the percentage of osseous bridging in the same semiquantitative manner.
The significant fusion rate differences between joints with and without ≥50% graft fill were consistent regardless of whether autograft or allograft was used and regardless of which joint was fused. The authors conclude that these findings “demonstrated that when a surgeon can eliminate bone-to-bone gaps in any joint intended for fusion,…such a joint has a significantly better chance of ultimately achieving fusion,” although they caution against “overpacking a joint with excessive graft material.” DiGiovanni et al. cite the need for further research “to determine the ideal amount of graft material required for a clinically relevant and impactful effect on fusion” and to help develop “graft materials that are easier to introduce and can be more precisely inserted into the intended fusion space.”
In diligent efforts to improve osseous bridges when performing spinal fusion surgery, orthopaedists have been using harvested allograft bone for more than a century and bone morphogenetic protein (BMP) for nearly a half century. Now, a European multicenter, randomized trial by Delawi et al., in the March 16, 2016 Journal of Bone & Joint Surgery, has compared overall success (defined as a combination of CT-determined fusion rates and clinical results at 12 months) between the two approaches among 113 patients.
This was a non-inferiority trial, and the BMP formulation used (Osigraft BMP-7, known commonly as OP-1 and available in the US in a similar formulation known as OP-1 Putty) was not non-inferior to iliac crest autograft. To clarify the potentially confusing double negative: OP-1 was less successful than autograft, due primarily to lower fusion rates. There were no significant between-group differences in clinical outcomes as measured by scores on the Oswestry Disability Index, although the authors added that “our follow-up period of one year may have been too short to show differences in clinical results.”
Delawi et al. conclude that, based on their findings, “use of OP-1 in place of autologous iliac crest bone graft in instrumented posterolateral lumbar fusions cannot be recommended.” That conclusion is echoed by commentator Jeffrey Coe, MD, who sees these findings as “another bit of evidence against the use of rhBMP-7 as a substitute for [iliac crest bone grafts] in posterolateral spinal fusion.”
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 cited in the February 17, 2016 Specialty Update on pediatric orthopaedics:
Guidelines and AUCs
–The AAOS updated its clinical practice guidelines on the treatment of pediatric diaphyseal femoral fractures1 and adopted appropriate use criteria (AUC) for pediatric supracondylar humeral fractures with vascular injury.2
–A matched case control study of surgical spinal procedures found that neuromuscular scoliosis, weight for age ≥95th percentile, ASA score of ≥3, and prolonged operative time were associated with a higher risk of surgical site infection.3
–Several groups, including the Scoliosis Research Society and POSNA, endorsed the definition of early-onset scoliosis as “scoliosis with onset less than the age of ten years, regardless of etiology.”4, 5
–A prospective randomized study found that preoperative education and orientation for scoliosis surgery paradoxically increased immediate postoperative anxiety among patients and caregivers, relative to controls who received standard perioperative information.6
–A randomized trial investigating perioperative blood loss and transfusion rates in patients undergoing posterior spinal arthrodesis for adolescent idiopathic scoliosis found that tranexamic acid and epsilon-aminocaproic acid reduced operative blood loss but not transfusion rates when compared with placebo.
–A study of 30 patients with severe stable slipped capital femoral epiphysis found that good or excellent results were achieved over 2.5 years in a higher proportion of those receiving a modified Dunn realignment compared with those treated with in situ fixation. The reoperation rate was greater in the in situ fixation cohort.7
–A prospective study analyzing complications after periacetabular osteotomy for acetabular dysplasia using the modified Clavien-Dindo grading scheme found grade III or IV complications in 5.9% of 205 patients, with a nonsignificant trend associating complications with male sex and obesity.
–A registry-based study found that, compared with matched controls, patients with Legg-Calve-Perthes disease had an elevated hazard ratio of 1.5 for ADHD, 1.3 for depression, and 1.2 for mortality. It remains unclear whether patients with Legg-Calve-Perthes disease would benefit from routine psychiatric screening.8
–A case control study of 822 injured athletes and 368 uninjured athletes found that overuse injuries represented 67.4% of all injuries. The risk of serious overuse injury was two times greater if the weekly hours of sports participation were greater than the athlete’s age in years.9
–A meta-analysis of initial nonoperative treatment compared with operative treatment of ACL tears in children and adolescents noted instability and pathologic laxity in 75% of patients with nonoperative treatment compared with 14% of patients following reconstruction.10
–A review of more than 4,400 supracondylar humeral fractures with isolated anterior interossesous nerve palsies but without sensory nerve injury or dysvasculartity found that postponing treatment for up to 24 hours did not delay neurologic recovery.
–A randomized controlled trial investigating the effectiveness of analgesics during intraossesous pin removal found that acetaminophen and ibuprofen were clinically equivalent to placebo in terms of pain reduction and heart rate.
Foot and Ankle
–A study exploring risk factors for failure of allograft bone after calcaneal lengthening osteotomy found a lower risk of failure with tricortical iliac crest allograft relative to patellar allograft. The risk of radiographic graft failure increased with patient age.11
–A prospective nonrandomized study of symptomatic planovalgus feet comparing subtalar arthroereisis with lateral column lengthening found similar postoperative improvements and complication rates in both groups after one year.12
Musculoskeletal Infection & Neuromuscular Conditions
–A cohort study of 869 children with osteomyelitis, septic arthritis, pyomyositis, or abscess concluded that routinely culturing for anaerobic, fungal, and acid-fast bacterial organisms is not recommended except in patients with a history of penetrating injury, immunocompromise, or failure of primary treatment.
–A prospective study comparing tendon transfers, botulinum toxin injections, and ongoing therapy in children with upper-extremity cerebral palsy found that tendon transfer demonstrated greater improvements than the alternatives in joint positioning during functional tasks and grip and pinch strength.
- American Academy of Orthopaedic Surgeons.Guideline on the treatment of pediatric diaphyseal femur fractures. 2015.http://www.aaos.org/Research/guidelines/PDFFguideline.asp.
- American Academy of Orthopaedic Surgeons.Appropriate use criteria: pediatric supracondylar humerus fractures with vascular injury. 2015.http://www.aaos.org/research/Appropriate_Use/pshfaucvascular.asp.
- Croft LD, Pottinger JM, Chiang HY, Ziebold CS, Weinstein SL, Herwaldt LA. Risk factors for surgical site infections after pediatric spine operations. Spine (Phila Pa 1976). 2015 Jan 15;40(2):E112-9
- El-Hawary R, Akbarnia BA. Early onset scoliosis – time for consensus. Spine Deformity. 2015 Mar;3(2):105-6
- Skaggs DL, Guillaume T, El-Hawary R, Emans J, Mendelow M, Smith J. Early onset scoliosis consensus statement, SRS Growing Spine Committee, 2015. Spine Deformity. 2015;3(2):107.
- Rhodes L, Nash C, Moisan A, Scott DC, Barkoh K, Warner WC Jr, Sawyer JR, Kelly DM.Does preoperative orientation and education alleviate anxiety in posterior spinal fusion patients? A prospective, randomized study. J Pediatr Orthop. 2015 Apr-May;35(3):276-9.
- Novais EN, Hill MK, Carry PM, Heare TC, Sink EL. Modified Dunn procedure is superior to in situ pinning for short-term clinical and radiographic improvement in severe stable SCFE. Clin Orthop Relat Res. 2015 Jun;473(6):2108-17. Epub 2014 Dec 12
- Hailer YD, Nilsson O. Legg-Calvé-Perthes disease and the risk of ADHD, depression, and mortality. Acta Orthop. 2014 Sep;85(5):501-5. Epub 2014 Jul 18.
- Jayanthi NA, LaBella CR, Fischer D, Pasulka J, Dugas L. Sports-specialized intensive training and the risk of injury in young athletes: a clinical case-control study. Am J Sports Med. 2015 Apr;43(4):794-801. Epub 2015 Feb 2.
- Ramski DE, Kanj WW, Franklin CC, Baldwin KD, Ganley TJ. Anterior cruciate ligament tears in children and adolescents: a meta-analysis of nonoperative versus operative treatment. Am J Sports Med. 2014 Nov;42(11):2769-76. Epub 2013 Dec 4.
- Lee IH, Chung CY, Lee KM, Kwon SS, Moon SY, Jung KJ, Chung MK, Park MS. Incidence and risk factors of allograft bone failure after calcaneal lengthening. Clin Orthop Relat Res. 2015 May;473(5):1765-74. Epub 2014 Nov 14.
- Chong DY, Macwilliams BA, Hennessey TA, Teske N, Stevens PM. Prospective comparison of subtalar arthroereisis with lateral column lengthening for painful flatfeet. J Pediatr Orthop B. 2015 Jul;24(4):345-53.
OrthoBuzz has reported previously on the 3D printing of implantable skeletal structures (click here for an example), but the materials used were metallic. Now, two new accomplishments with 3D printing have produced material that mimics the physiochemical properties and porous structure of real bone.
First, students from California State University in Long Beach created the LuxNova OsBot 3D printer. The students say that the OsBot can replicate the unique and complex structure of human bone tissue down to the micro and nano levels.
Meanwhile, in China, the Xi’an Particle Cloud Advanced Materials Technology Co. has wrapped up animal testing on a similar bioprinting device and is poised to enter human trials. The device uses both UV light and heat to “laminate” binder material until a bonelike structure is fabricated. In rabbits, the 3D-printed bone exhibited new bone-cell activity on its surface almost immediately after implantation.
Theoretically, surgeons could use 3D-printed bone grafts to replace cancerous or severely traumatized bone tissue, obviating the need for amputation or cadaver grafts.