Purpose: Missed Monteggia fracture dislocation in children is a serious condition. The treatment of this rare condition is controversial and reports on the long-term outcome are sparse. We present a series of patients treated with open reduction and ulnar osteotomy with a mean long-term follow-up of 8 years (range 3–17). Methods: All 16 patients had Bado type 1 (anterior radial head) dislocation. The mean delay from injury to surgery was 17 months (range 1–83). Bilateral radiographs, Oxford Elbow Score, strength measurements, and range of motion were obtained in all patients. Results: There were no major complications to surgery. The radiographic results showed ten patients with reduction of the radial head and with no arthrosis, four patients with arthrosis or subluxation, and two patients with a dislocated radial head. We found a significant correlation between radiographic outcome and delay to ulnar osteotomy ( P = 0.03). Typical clinical findings were a small but significant extension deficit and mean loss of supination of 10° (range 0–90, P < 0.01). Ligament reconstruction or transfixation of the radial head did not influence the radiographic or clinical outcome. Conclusions: Case reports of similar patients treated conservatively demonstrate high morbidity, and, therefore, open reduction and ulnar osteotomy seemed justified. However, this study underlines the importance of minimizing the delay between injury and ulnar osteotomy. If surgery is performed within 40 months after injury, good to fair long-term radiographic results can be obtained. Open reduction and ulnar osteotomy were performed because patients treated conservatively demonstrate high morbidity.

We have studied the beneficial effects of a hydroxyapatite (HA) coating on the prevention of the migration of wear debris along the implant-bone interface. We implanted a loaded HA-coated implant and a non-coated grit-blasted titanium alloy (Ti) implant in each distal femoral condyle of eight Labrador dogs. The test implant was surrounded by a gap communicating with the joint space and allowing access of joint fluid to the implant-bone interface. We injected polyethylene (PE) particles into the right knee three weeks after surgery and repeated this weekly for the following five weeks. The left knee received sham injections. The animals were killed eight weeks after surgery. Specimens from the implant-bone interface were examined under plain and polarised light.

In paediatric orthopaedics, deformities and discrepancies in length of bones are key problems that commonly need to be addressed in daily practice. An understanding of the physiology behind developing bones is crucial for planning treatment. Modulation of the growing bone can be performed in a number of ways. Here, we discuss the principles and mechanisms behind the techniques. Historically, the first procedures were destructive in their mechanism but reversible techniques were later developed with stapling of the growth plate being the gold standard treatment for decades. It has historically been used for both angular deformities and control of overall bone length. Today, tension band plating has partially overtaken stapling but this technique also carries a risk of complications. The diverging screws in these implants are probably mainly useful for hemiepiphysiodesis. We also discuss new minimally invasive techniques that may become important in future clinical practice.

In each femoral condyle of 8 Labrador dogs, a non weight-bearing hydroxyapatite-coated implant was inserted surrounded by a 3 mm gap. Each gap was filled with bone allograft or ProOsteon with or without OP-1 delivered in a bovine collagen type I carrier (OP-1 device). 300 w g OP-1 was used in the 0.75 cc gap surrounding the implant. After 3 weeks, the OP-1 device enhanced implant fixation by 800% (p < 0.05) in the ProOsteon group, but OP-1 had no significant effect on implant fixation in the allograft group. By adding the OP-1 device, the volume fraction of woven bone close to the implant increased from 12% to 20% (p < 0.05) in the bone allograft group and from 6% to 25% (p < 0.05) in the ProOsteon group. The volume fraction of bone allograft decreased from 29% to 9% (p < 0.05) in the OP-1 treated group versus 33% to 30% in the allograft group not treated with OP-1. No resorption of ProOsteon was found. In conclusion, OP-1 accelerates resorption of bone allograft and enhances new bone formation around cementless implants grafted with bone allograft or semisynthetic hydroxyapatite bone substitute. Our findings do not support the use of ProOsteon alone around cementless implants.

Hydroxyapatite (HA) particles have long been suspected to disintegrate from implant surfaces, become entrapped in joint spaces of orthopaedic bearing couples, and start a cascade leading to progressive polyethylene (PE) wear, increased osteolysis, and aseptic loosening. We compared cup revision at 15 years’ followup in a randomized group of patients with 26 cementless THA components with titanium (Ti) versus first-generation HA coating. We also assessed radiographic PE wear and osteolysis to the 12-year followup or end point revision at a minimum of 5 years (mean, 10.9 years; range, 5–12.6 years). Two Ti-coated cups (17%) and eight HA-coated cups (57%) were revised at 15 years’ followup. Femoral head penetration rate was 0.46 mm/year (standard deviation, 0.26) with the HA-coated cups (n = 12) and 0.38 mm/year (standard deviation, 0.14) with the Ti-coated cups (n = 10); we observed a wide variance of linear wear with the HA-coated cups. We also observed a positive association between high wear rate and revision, and between a high volume of osteolysis and revision. Our findings suggest inferior survival of medium-thickness spray-dried HA-coated cups with individual cases of excessive PE wear and premature cup failure. These findings apply to first-generation modular cups and may not apply to other cup designs and new HA-coating technologies. Level of Evidence: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

We compared processed morselized bone allograft with fresh-frozen bone graft around noncemented titanium implants. Also, the influence of platelet-rich plasma (PRP) in combination with bone allograft was evaluated. Analysis was based on implant fixation and histomorphometry. PRP was prepared by isolating the buffy coat from autologous blood samples. Bone allograft was used fresh-frozen or processed by defatting, freeze drying, and irradiation. Cylindrical hydroxyapatite-coated titanium implants were inserted bilaterally in the femoral condyles of eight dogs. Each implant was surrounded by a 2.5-mm concentric gap, which was filled randomly according to the four treatment groups—group 1: fresh-frozen bone allograft; group 2: processed bone allograft; group 3: fresh-frozen bone allograft + PRP; group 4: processed bone allograft + PRP. Histological and mechanical evaluation demonstrated no influence of bone allograft processing. Even though the level of platelet in PRP was 7.7 times that found in whole blood, we found no improvement of bone formation or implant fixation by adding PRP. Nous avons comparé l’allogreffe osseuse morcelée avec la greffe osseuse fraîche congelée autour d’implants en titane non-cimentés. L’influence du plasma riche en plaquettes (PRP) dans la combinaison avec l’allogreffe osseuse a aussi été évaluée. L’analyse était basée sur la fixation de l’implant et l’histomorphométrie. Le PRP a été préparé en isolant la couche leuco-plaquettaire du sang autologue après centrifugation. L’allogreffe osseuse a été utilisé fraiche et congelée ou a été traité par délipidation, lyophilisation et irradiation. Les implants de titane cylindriques enduit d’hydroxyapatite ont été insérés bilatéralement dans le condyle fémoral de huit chiens. Chaque implant a été entouré par un intervalle concentrique de 2.5 mm qui a été rempli de façon aléatoire d’après les quatre groupes de traitement—groupe-1: allogreffe congelée fraiche; groupe-2: allogreffe traitée; groupe-3: allogreffe congelée fraiche+PRP; groupe-4: allogreffe traitée+PRP. L’évaluation histologique et mécanique n’a démontré aucune influence du traitement de l’allogreffe osseuse. Bien que le niveau de plaquettes dans le PRP fût 7.7 fois celui du sang total, nous n’avons trouvé aucune amélioration de la formation osseuse ou de la fixation de l’implant en ajoutant du PRP.