GROWTH DISTURBANCES ASSOCIATED WITH UNTREATED BENIGN BONE CYSTS

Background: The occurrence of benign bone cysts adjacent to an active physis may be associated with a physeal arrest. That arrest may result from physeal penetration of the cysts itself, secondary pathologic fracture or the result of surgical curettage. Methods : The pre-treatment X-rays of patients attending the Bone Tumor Clinic at the Children's Hospital and Medical Center were reviewed. Those patients presenting with a bone cyst were identified and the affected side was compared to the normal side in order to determine growth discrepancies. Results: Three cases of benign bone cysts are presented that were located adjacent to a growing physis and produced growth disturbance in the absence of surgical intervention. Conclusions: The risk of growth disturbance in itself should not be a contraindication to surgical intervention.     

Elastic stable intramedullary nailing for displaced proximal humeral fractures in older children

Purpose To demonstrate the effectiveness of intramedullary fixation of severely displaced proximal humeral physeal fractures in skeletally immature children using the elastic stable intramedullary nail (ESIN). Methods Retrospective recruitment of 14 patients aged 10–15-years old with severely displaced proximal humeral physeal fractures between 1999 and 2004 in a single regional specialist paediatric orthopaedic hospital. The fractures were graded using the Neer classification; severe displacement constituted Neer II–IV or displacement >1 cm and angulation >45°. Patients were followed up and assessed using the Disabilities of the Arm, Shoulder and Hand score (DASH) and the Neer Shoulder score. Radiographs were assessed for deformity. Subjective satisfaction was assessed. Results Fourteen patients with mean follow-up of 30 months (12–66 m) from surgery. All fractures were radiologically united at a median time of eight weeks (7–10 weeks). At follow-up, Neer Shoulder mean score was 96.79 (range 83–100) and DASH mean score 2.26 (0–7.5). Subjectively 71% were very satisfied and 29% were satisfied. Conclusions We commend stabilisation using ESIN in the management of the displaced proximal humeral physeal fracture in older children, once reduction of the fracture has been achieved by either closed or open means. ESIN is safe and allows early return to pre-injury function.     

Central connections of the toad neural lobe as shown by retrograde neuronal labeling: classical and new connections

Iontophoretic deposit of horseradish peroxidase (HRP) in the hypophysial neural lobe (NL) of the toad labeled neurons in the classical neurosecretory preoptic magnocellular nucleus. Further, a number of labeled neurons appeared in the whole extension of the periventricular and medial preoptic nuclei. The latter were continuous dorsally with two other labeled areas known as the bed nucleus of the hippocampal commissure (which appears to be homologous to the subfornical organ in mammals) and the ventromedial thalamic area of Frontera. The possible functional role of many of these afferents to the neural lobe is unknown because all types of neurons were labeled in the projecting zones and, in addition, many are outside of the generally recognized neurosecretory groups.     

Fracture of the distal end of the fibula through a persistent physis in an adult with fracture of the medial malleolus

 A 26-year-old woman was injured in a motor vehicle accident and sustained a bimalleolar fracture of the right ankle. Radiographs revealed a shearing fracture of the medial malleolus and a gap in the distal end of the right fibula that resembled epiphysiolysis in children. Fracture of the distal end of the fibula through a persistent physis was suspected. Histological examination of material obtained from the fracture site during surgery revealed remnants of hyaline cartilage. We believe that the fracture occurred at a persisitent physis of the distal end of the fibula. Received: July, 10, 2002 / Accepted: October 21, 2002 Offprint requests to: N. Yamamoto     

Accelerated hypertrophic chondrocyte kinetics in GDF‐7 deficient murine tibial growth plates

The Growth/Differentiation Factors (GDFs) are a subgroup of the Bone Morphogenetic Proteins (BMPs) well known for their role in joint formation and chondrogenesis. Mice deficient in one of these signaling molecules, GDF‐5, have recently been shown to exhibit a decreased rate of endochondral bone growth in the proximal tibia due to a significantly longer hypertrophic phase duration. GDF‐7 is a related family member, which exhibits a high degree of sequence identity with GDF‐5. The purpose of the present study was to determine whether GDF‐7 deficiency also alters the endochondral bone growth rate in mice and, if so, how this is achieved. Stereologic and cell kinetic parameters in proximal tibial growth plates from 5‐week‐old female GDF‐7 ?/? mice and wild type control littermates were examined. GDF‐7 deficiency resulted in a statistically significant increase in growth rate (+26%; p = 0.0084) and rate of cell loss at the chondrosseous junction (+25%; p = 0.0217). Cells from GDF‐7 deficient mice also exhibited a significantly shorter hypertrophic phase duration compared to wild type controls (?27%; p = 0.0326). These data demonstrate that, in the absence of GDF‐7, the rate of endochondral bone growth is affected through the modulation of hypertrophic phase duration in growth plate chondrocytes. These findings further support a growing body of evidence implicating the GDFs in the formation, maturation, and maintenance of healthy cartilage. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:986–990, 2008     

Osteosynthesis with the Hook-Pin in Slipped Capital Femoral Epiphysis

Osteosynthetic materials, such as metallic nails, screws, pins, and bone pegs, used in the surgical treatment of slipped capital femoral epiphysis, have caused peroperative problems because of increased displacement of the femoral head and postoperative problems because of bone resorption and growth of the femoral neck, resulting in loosening of the osteosynthetic material and reslipping of the femoral head. Premature closure of the growth plate and shortening of the femoral neck have also been registered.

In order to avoid these problems, a hook-pin was developed. This device has now been in use for a period of 6 years and has been applied in 38 cases, the pin being placed in a drilled channel with the hook in the femoral head. The operation has been performed on the slipped side with or without reduction of displacement and on the asymptomatic side. Seventy-five hips have been operated on.

The advantages of the hook-pin and of the operative technique are presented. No avascular necrosis has been noted in 74 hips pinned in situ or after closed reduction. Avascular necrosis occurred in one hip after femoral neck osteotomy. All 28 asymptomatic hips and 27 out of 37 hips with slipped epiphyses showed no tendency toward premature closure during a postoperative observation period of 1-6 years. The growth in length of the femoral neck was found to be up to 15 mm, almost the same on the slipped side as on the asymptomatic side.

Only one of the 75 hips required reoperation because of resorption around the hook-pin.

After the end of the growth period the hook-pin was extracted in 19 hips without problems.     

Growth potential of different zones of the growth plate—an experimental study in rabbits

Despite clinical efforts to treat growth disturbances only little is known about the growth potential of the different zones of the growth plate. The aim of this study was to investigate the growth potential of different zones of the growth plate. A total of 20 New Zealand White rabbits were used for this experiment. The right and left ulna of each animal were used resulting in a total of 40 ulnae. Animals were assigned into five groups. In groups I and II resection of the metaphyseal (n = 12) or the epiphyseal (n = 6) segment of the growth plate was performed. In group III resection of the growth plate and re‐implantation was performed (n = 6). In group IV the growth plate was resected and re‐implanted after a 180° rotation (n = 6). Animals in group V served as controls. Histologic and radiologic examinations were performed to evaluate the growth process at 1, 2, 4, and 12 weeks following surgery. In group I, III, and IV temporary growth disturbance which was compensated within a short time was observed. Resection of the epiphyseal part resulted in growth arrest of the distal ulna in combination with normal growth of the radius which led to and valgus deformity of the limb. The results of this study indicate the importance of the reserve zone for the functioning of the growth plate. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:162–168, 2012