Development of a novel murine delayed secondary fracture healing in vivo model using periosteal cauterization.

INTRODUCTION: Delayed union and nonunion development remain a major clinical problematic complication during fracture healing, with partially unclear pathophysiology. Incidences range from 5 to 40% in high-risk patients, such as patients with periosteal damage. The periosteum is essential in adequate fracture healing, especially during soft callus formation. In this study, we hypothesize that inducing periosteal damage in a murine bone healing model will result in a novel delayed union model. MATERIALS AND METHODS: A mid-shaft femoral non-critically sized osteotomy was created in skeletally mature C57BL/6 mice and stabilized with a bridging plate. In half of the mice, a thin band of periosteum adjacent to the osteotomy was cauterized. Over 42 days of healing, radiographic, biomechanical, micro-computed tomography and histological analysis was performed to assess the degree of fracture healing. RESULTS: Analysis showed complete secondary fracture healing in the control group without periosteal injury. Whereas the periosteal injury group demonstrated less than half as much maximum callus volume (p < 0.05) and bridging, recovery of stiffness and temporal expression of callus growth and remodelling was delayed by 7-15 days. CONCLUSION: This paper introduces a novel mouse model of delayed union without a critically sized defect and with standardized biomechanical conditions, which enables further investigation into the molecular biological, biomechanical, and biochemical processes involved in (delayed) fracture healing and nonunion development. This model provides a continuum between normal fracture healing and the development of nonunions.

Comparison of Negative Pressure Wound Therapy and Conventional Therapy for Cranial Bone-exposed Wounds in Rabbits.

BACKGROUND: Bone-exposed wounds with intact or defected periosteum are difficult to heal. To provide relevant experimental evidence for guidance of clinical therapy, we established a rabbit model to compare the efficacies of negative pressure wound therapy (NPWT) and conventional guaze dressing therapy on the healing of cranial bone-exposed wounds. METHODS: Full-thickness excisional circular wounds of 2.0 cm in diameter with exposed bones covered with or without periosteum were created at the parietal regions in 88 rabbits that were further randomly divided into the following treatment groups: periosteum-intact wounds treated with conventional vaseline gauze dressings (P + Control group), periosteum-intact wounds treated with NPWT (P + NPWT group), periosteum-lacking wounds treated with conventional vaseline gauze dressings (P-Control group), and periosteum-lacking wounds treated with NPWT (P-NPWT group). The wounds of NPWT groups were treated using a negative pressure therapy assembly that was set at a continuous pressure of -125 mm Hg for 7 days, then covered with vaseline gauze. The wound healing rates, wound infection rates, hydroxyproline content, and wound tissue histology were determined and evaluated. RESULTS: The NPWT shortened the wound healing time by approximately 5 days when compared with the conventional gauze therapy. The histological characterization of wound tissues showed that NPWT decreased the inflammatory cells infiltration, accelerated reepithelialization and facilitated the organization of collagen fibers into neat layers on postoperative day (POD) 10. The NPWT enhanced bacterial clearances, reduced infection rates and increased the hydroxyproline contents in both types of wounds on PODs 10 and 15. The immunohistochemical staining of CD31 showed the NPWT treatment resulted in a significantly increased and persistent angiogenesis, and the wounds treated with NPWT showed well developed and more functional vessels at POD 7 compared with control. CONCLUSIONS: The NPWT is a more effective therapy for bone-exposed wounds than conventional guaze dressing therapy. The NPWT can promote bone-exposed wounds healing by increasing collagen contents and vessels densities while reducing inflammatory cells infiltration, reducing wound infection rates, and inducing an ordered collagen arrangement.

Traumatic avulsion of the superior extensor retinaculum of the ankle as a cause of subperiosteal haematoma of the distal fibula in children. A retrospective study of 7 cases.

OBJECTIVE: To describe a new sonographic feature for a traumatic lesion of the ankle in children. MATERIALS AND METHODS: We present a retrospective review of superior extensor retinaculum (SER) avulsions diagnosed by ultrasound (US) as a cause of subperiosteal haematoma (SPH) and periosteal apposition of the distal fibula in seven children (3 girls and 4 boys, mean age 13.4 years; age range 10-15 years) after an inversion trauma of the ankle. Two children were subsequently examined with magnetic resonance imaging (MRI). RESULTS: At the acute phases (6 children), US showed a hypoechoic collection with periosteal elevation at the fibular insertion of the SER. The fibular cortex and growth plate were unremarkable. The SPH was isolated in three cases and associated with an anterior talofibular ligament sprain in four. In two cases, MRI confirmed the SER periosteal avulsion and the integrity of the distal fibula. At the later phase (one child), US showed a periosteal apposition at the fibular insertion of the SER with hypoechoic thickening of the SER and power Doppler hyperaemia. CONCLUSION: This is the first sonographic description of SER avulsion as cause of SPH of the distal fibula in children. SPH in children should not be considered as pathognomonic of a Salter-Harris type 1 lesion of the distal fibula. Later, it may be responsible for persistent ankle pain. Therefore, SER may be systematically explored in children during US examination of the ankle after trauma.

Association of a Subperiosteal Hematoma With Minor Injury.

An intraorbitalsubperiosteal hematoma is a rare clinical entity that is usually caused by head trauma. The authors experienced a patient involving an intraorbital hemorrhage that was associated with minor injury in the forehead and that required surgical decompression. The authors describe this rare case involving an intraorbitalsubperiosteal hematoma that occurred in a conscious young boy who had no remarkable head injury and who had sudden onset of proptosis. Three-dimensional computed tomography, which was conducted with a volume-rendering method, was very useful, and the transorbital approach that was used to remove the hematoma was very effective. The patient showed good recovery. The pathogenesis of the intraorbitalsubperiosteal hemorrhage could not be fully explained, and, thus, the authors suggest that a possible pathogenesis involved the migration of the hemorrhage from the forehead into the intraorbital region.

Reconstruction of a functional gliding surface with extensor retinaculum in extensor tendon reconstruction in the digits.

BACKGROUND: Tendon gliding is key to optimal recovery of hand function after complex tendon injuries. Gliding is facilitated by a low-friction gliding surface that is normally provided by the periosteum of the underlying bone. However, significant injuries may damage the periosteum, which must be reconstructed to allow uninterrupted tendon excursion. The absence of the periosteum may compromise a tendon's ability to glide freely, thereby limiting the range of motion. METHODS: Six digits in 4 patients with complex, composite soft tissue defects involving tendon, periosteum, and skin of the hand underwent surgical repair. Each digit had disruption of the bony cortex underlying the tendon injury including periosteal loss. Through an incision on the dorsum of the ipsilateral wrist, an extensor retinaculum graft corresponding to the size of the periosteal defect was harvested. It was then sutured into place over the bare cortex to replace the lost periosteum. RESULTS: All the 6 digits in the 4 patients had complete return to function. Additionally, all patients had near normal strength in the repaired hand along with excellent tendon excursion in both flexion and extension. The average time of follow-up of this series of patients was 1.5 years. CONCLUSIONS: Extensor retinaculum grafting to replace lost periosteum is a technique that is easily used, uses locally available autogenous tissues, and produces excellent tendon function. Additionally, the histologic similarities between extensor retinaculum and periosteum add scientific merit to this novel approach. On the basis of our experience, we recommend the use of extensor retinaculum for periosteal reconstruction to provide an adequate gliding surface for a reconstructed tendon.

Arthroscopic findings in the recurrent anterior instability of the shoulder.

BACKGROUND: A recurrent anterior shoulder dislocation consists of a variety of lesion types. OBJECTIVES: To evaluate the pathological classification of recurrent anterior dislocation of the shoulder joint under arthroscopy. METHODS: Thirty-one patients with recurrent anterior shoulder dislocation were inspected by arthroscopy, including 23 males and 8 females, with a mean age of 35.1 (18-46) years. The patients were divided into two groups: 17 with shoulder dislocation and hyper-laxity (the hyper-laxity group) and 14 with only traumatic shoulder dislocation (the trauma group). All the patients were assessed by arthroscopy for pathological changes, and the differences in the pathological changes were compared between the two groups. RESULTS: All these 31 patients suffered from anteroinferior labrum injury. Twenty-five had Hill-Sachs injury; 27, bone or cartilage injury of anteroinferior glenoid; 16, SLAP injury; and 5, rotator cuff injury. Bankart injury occurred more in the trauma group, and anterior labroligamentous periosteal sleeve avulsion injury and glenolabral articular disruption injury were more in the hyper-laxity group. Bone or cartilage injury of anteroinferior glenoid was more noticed in the trauma group. CONCLUSIONS: Significant differences are found under arthroscopy in the pathological changes of recurrent anterior shoulder dislocation between the purely traumatic group and the hyper-laxity group. The pathological changes in the trauma group were more severe than in the hyper-laxity group.

Ossification of subperiosteal hematoma: the potential of periosteal osteogenesis in cranioplasty.

BACKGROUND: Subperiosteal hematoma is the accumulation of blood between the periosteum and the skull, which commonly occurs in the neonatal period but rarely in other ages. Subperiosteal hematoma can be self-absorbed in most cases and occasionally may cause ossification. MATERIALS AND METHODS: This study reports a case of subperiosteal hematoma formed in a 16-year-old adolescent boy after a minor trauma. Because the hematoma did not disappear for more than a month after the trauma, the patient was treated with multiple hematoma punctures. However, the hematoma recurred and led to ossification. Finally, the patient underwent surgical treatment. RESULTS: Finally, the ossification associated with the hematoma was treated through surgery. The head contour recovered normally. CONCLUSIONS: The occurrence of hematoma ossification in the 16-year-old patient suggests that the periosteum has great potential for osteogenesis. This is likely caused by the joint action of some active factors in the blood and a certain tension of the hematoma on the local periosteum. This case provides the following thoughts. (1) A subperiosteal hematoma that has not been absorbed after 1 month should be treated promptly to avoid ossification. Once ossification has occurred, the hematoma should be treated surgically. (2) The potential for periosteal osteogenesis is great, which may provide a new thought for cranioplasty.

Validation of MRI classification system for tibial stress injuries.

OBJECTIVE: The purpose of our study was to compare an MRI classification system for tibial stress injuries with semiquantitative MR features of injury severity and clinical outcome. MATERIALS AND METHODS: Two musculoskeletal radiologists retrospectively reviewed in consensus the MR findings of 142 tibial stress injuries to quantify the degree of periosteal and bone marrow edema and grade the injuries using the Fredericson classification system (grade 1 = periosteal edema only, grade 2 = bone marrow edema visible on T2-weighted images, grade 3 = bone marrow edema visible on T1-weighted and T2-weighted images, grade 4a = multiple focal areas of intracortical signal abnormality, and grade 4b = linear areas of intracortical signal abnormality). Kruskal-Wallis tests were used to determine the relationship between the grade of stress injury and the degree of periosteal and bone marrow edema and the time to return to sports activity. RESULTS: Grade 4b injuries had significantly (p < 0.002) more severe and grade 1 injuries less severe periosteal and bone marrow edema than grades 2, 3, and 4a injuries. Grade 4b injuries had significantly (p < 0.002) longer time and grade 1 injuries shorter time to return to sports activity than grades 2, 3, and 4a injuries. There was no significant difference (p = 0.06-0.79) among grades 2, 3, and 4a injuries in the degree of periosteal and bone marrow edema and the time to return to sports activity. CONCLUSION: Grades 2, 3, and 4a stress injuries had similar degrees of periosteal and bone marrow edema and similar time to return to sports activity, which suggests that these three grades can be combined into a single category in an abbreviated Fredericson classification system.

MRI diagnosis of trapped periosteum following incomplete closed reduction of distal tibial Salter-Harris II fracture.

Irreducible fracture of the distal tibial physis due to interposed soft tissue including periosteum is well documented in the orthopedic literature but is uncommon. This condition has been associated with subsequent growth disturbance and requires open reduction. There are very few prior reports of MRI depiction of soft tissue interposition and none of periosteal interposition in the distal tibial physis. This is a relatively common location of physeal injury and related growth disturbance. We present a case of periosteum trapped in the distal tibial physis, diagnosed on MRI, in a Salter-Harris II fracture and its management implications.

Periosteal entrapment in distal femoral physeal fractures: harbinger for premature physeal arrest ?

We report on two patients who sustained Salter-Harris II fractures of the distal femur with physeal widening after being tackled in football games. Preoperative MRI indicated entrapped periosteum at the physeal fracture site for both patients. Both patients underwent open reduction of the physeal fracture with removal of the entrapped periosteum and achieving an anatomic reduction. Follow-up MRI's revealed premature physeal arrest. Subsequent procedures were performed to address sequelae of premature physeal arrest. The presence of physeal widening and entrapped periosteum may reflect high-energy trauma to the physis. This can result in injury to both the epiphyseal blood supply and to the physeal cartilage (germinal zone) resulting in physeal arrest despite anatomic reduction after removal of the entrapped periosteum. Upon literature review, pre-operative MRI demonstrating entrapped periosteum has not been previously reported. We hypothesize that the presence of entrapped periosteum following distal femoral physeal fractures may be associated with an increased risk for premature physeal arrest.

Morphoscopic analysis of experimentally produced bony wounds from low-velocity ballistic impact.

Understanding how bone behaves when subjected to ballistic impact is of critical importance for forensic questions, such as the reconstruction of shooting events. Yet the literature addressing microscopic anatomical features of gunshot wounds to different types of bone is sparse. Moreover, a biomechanical framework for describing how the complex architecture of bone affects its failure during such impact is lacking. The aim of this study was to examine the morphological features associated with experimental gunshot wounds in slaughtered pig ribs. We shot the 4th rib of 12 adult pigs with .22 mm subsonic bullets at close range (5 cm) and examined resultant wounds under the light microscope, scanning electron microscope SEM and micro tomograph µCT. In all cases there was a narrow shot channel followed by spall region, with evidence of plastic deformation with burnishing of the surface bone in the former, and brittle fracture around and through individual Haversian systems in the latter. In all but one case, the entrance wounds were characterized by superficially fractured cortical bone in the form of a well-defined collar, while the exit wounds showed delamination of the periosteum. Inorganic residue was evident in all cases, with electron energy dispersive spectroscopy EDS confirming the presence of carbon, phosphate, lead and calcium. This material appeared to be especially concentrated within the fractured bony collar at the entrance. We conclude that gunshot wounds in flat bones may be morphologically divided into a thin burnished zone at the entry site, and a fracture zone at the exit.

Bone marrow-derived cells in palatal wound healing.

OBJECTIVE: Myofibroblasts are responsible for contraction and scarring after cleft palate repair. This leads to growth disturbances in the upper jaw. We hypothesized that cells from the bone marrow are recruited to palatal wounds and differentiate into myofibroblasts. METHODS: We transplanted bone marrow from green fluorescent protein (GFP)-transgenic rats into lethally irradiated wild-type rats. After recovery, experimental wounds were made in the palatal mucoperiosteum, and harvested 2 weeks later. GFP-expressing cells were identified using immunostaining. Myofibroblasts, activated fibroblasts, endothelial cells, and myeloid cells were quantified with specific markers. RESULTS: After transplantation, 89 ± 8.9% of mononuclear cells in the blood expressed the GFP and about 50% of adherent cells in the bone marrow. Tissue obtained during initial wounding contained only minor numbers of GFP-positive cells, like adjacent control tissue. Following wound healing, 8.1 ± 5.1% of all cells in the wound area were positive, and 5.0 ± 4.0% of the myofibroblasts, which was significantly higher than in adjacent tissue. Similar percentages were found for activated fibroblasts and endothelial cells, but for myeloid cells it was considerably higher (22 ± 9%). CONCLUSIONS: Bone marrow-derived cells contribute to palatal wound healing, but are not the main source of myofibroblasts. In small wounds, the local precursor cells are probably sufficient to replenish the defect.

Radiofrequency energy on cortical bone and soft tissue: a pilot study.

BACKGROUND: Radiofrequency-generating energy devices have been used clinically in musculoskeletal procedures to provide hemostasis and capsular shrinkage (thermal capsulorrhaphy). However, the dose-effects are not well known. QUESTIONS/PURPOSES: We therefore determined dosage effects of radiofrequency energy on bone, skin incisions, and joint capsule in sheep. METHODS: Five mature sheep had six 2.5-cm(2) tibial periosteal defects and six 1.0-cm skin incisions assigned to six treatments varying by watts and fluence (f = watts . seconds/cm(2)): (1) untreated control, (2) 50 W for 9.5 seconds (190f; n = 5), (3) 110 W for 4.3 seconds (190f; n = 5), (4) 170 W for 2.8 seconds (190f; n = 5), (5) 170 W for 5.6 seconds (380f; n = 5), or (6) 170 W for 8.4 seconds (570f; n = 5). Outcomes included hemostasis, contraction, healing, and histomorphometry for inflammation and necrosis at 2 weeks. RESULTS: Radiofrequency energy application on skin at 190f or greater had more than 80% hemostasis and dose-dependent contraction, inflammation, and necrosis. Radiofrequency energy application on bone had good (70%) hemostasis at 190f and complete (> 95%) hemostasis at 380f and 570f, without histologic or clinically detectable necrosis. CONCLUSIONS: Hemostasis can be achieved with radiofrequency energy at 190f in skin and bone. Bone necrosis was not detected at up to 570f. Using fluence greater than 190f in skin achieved dose-dependent necrosis and incisional contraction. CLINICAL RELEVANCE: Radiofrequency energy can be used on bone and skin for hemostasis, but potential incisional complications, such as necrosis and an atypical firm and desiccated surface, should be expected.

Growing skull fracture with an atypical mechanism: a case report.

Growing skull fractures (GSFs) are well-known but rare causes of pediatric head trauma. They generally occur several months after a head injury, and the main lesion is located under the periosteum. We herein report a case involving a 3-month-old boy with GSF that developed by a different mechanism than previously considered. It developed 18 days after the head injury. A large mass containing cerebrospinal fluid and brain tissue was present within the periosteum. A good outcome was obtained with early strategic surgery. Injury to the inner layer of the periosteum and sudden increase in intracranial pressure might be related to GSF in this case.

Posterior periosteal disruption in Salter-Harris Type II fractures of the distal femur: evidence for a hyperextension mechanism.

OBJECTIVE: Patterns of periosteal disruption are important factors in assessing the mechanism of injury of radiologically evident Salter-Harris (SH) fractures. The purpose of this study is to assess the frequency of posterior periosteal disruption on MRI in radiographically occult or subtle SH type II fractures of the distal femur and to evaluate associated soft-tissue findings that support a hyperextension mechanism of injury. CONCLUSION: We found that all children in our experience with occult or subtle SH type II fractures of the distal femur have posterior periosteal disruption and other MRI findings to indicate a hyperextension mechanism of injury. Direct indicators of fracture may be inconspicuous, and the presence of posterior periosteal disruption is a clue that should prompt a search for other features of this serious pediatric injury, which may be followed by limb shortening or angular deformity.

Traumatic subperiosteal pseudoaneurysm: rare cause of subperiosteal hematoma.

Subperiosteal hematoma arises usually after blunt trauma to the bone. It is due to disinsertion or rupture of a muscle tendon or injury of nutrient artery of bone. Subperiosteal hematoma is a rare condition and develops mainly in the orbit because the periosteum is more loosely attached to the bone. Thus, few cases of subperiosteal hematoma in iliac bone are reported. Traumatic pseudoaneurysm develops mainly after penetrating or blunt trauma. It can be easily diagnosed by intravenous contrast computed tomography or magnetic resonance imaging by seen extravasation of contrast dye. We present a case of subperiosteal hematoma with subperiosteal pseudoaneurysm after blunt pelvic trauma in a 17-year-old adolescent boy. The pseudoaneurysm arose from a branch of superior gluteal artery, but it was not seen in the initial contrast computed tomography scan.

The effects of early or late treatment of osteochondral defects on joint homoeostasis: an experimental study in rabbits.

A 3.5 x 4 mm tubular osteochondral defect was created on the right medial femoral condyles of 51 adult rabbits. In the control group (CG), defects were left untreated. In the early-(ETG) and late-(LTG) treatment groups, defects were treated by an osteoperiosteal graft 1 and 12 weeks, respectively, after the index procedure. Synovial fluid (SF) samples were collected regularly and proteoglycan fragments (PF), total collagen (TC) and collagenase (MMP-1) levels were measured. Rabbits were killed at 4 (early period), 12 (intermediate period), or 24 (late period) weeks postoperatively. Histological examination indicated a more successful healing in both grafting groups than in the CG, but without any difference at any time period between the grafting groups. In the CG, PF, and TC levels in SF increased continuously until the late period, indicating an ongoing degenerative activity in the joints. In contrast, SF marker levels in both grafting groups indicated that normalization in joint metabolism could be achieved-at least partially-after treatment. However, PF levels in the SF showed that the treatment of defects in earlier stages might result in better outcomes since the negative effects were more prominent in chronic stages, presumably due to the more prolonged period of disturbed homeostasis. Thus, histological values and SF marker levels indicated that treatment of osteochondral defects at any time of the disease had a positive effect on healing when compared to no treatment. Early treatment might better assist the recovery of joint homeostasis than late treatment.

Fracture Pattern and Periosteal Entrapment in Adolescent Displaced Distal Tibial Physeal Fractures: A Magnetic Resonance Imaging Study.

OBJECTIVES: To investigate the fracture pattern and periosteal entrapment in adolescent distal tibial physeal fractures. DESIGN: Retrospective case series. SETTING: Level I academic trauma center. PATIENTS/PARTICIPANTS: Fifty patients (10-16 years of age) with displaced Salter-Harris type II, III, or IV distal tibial physeal fractures were retrospectively reviewed. INTERVENTION: Periosteal involvement, fracture pattern. MAIN OUTCOME MEASUREMENTS: We investigated the incidence and location of periosteal entrapment in those fractures and the angle of the fracture plane of metaphyseal fragments on axial plane by using magnetic resonance imaging. RESULTS: Of the 15 type II, 12 type III (4 malleolar and 8 Tillaux), and 23 type IV (2 malleolar and 21 triplane) fractures, 72.0% (36/50) presented with periosteal entrapment. Among all type II and triplane fractures, periosteal entrapment was observed in the anterolateral corner when there was any displacement on that corner. By contrast, only 1 of 8 Tillaux fractures presented with periosteal entrapment. In almost all supinated foot injuries of type II and triplane fractures, the metaphyseal fracture line was parallel to the intermalleolar axis on axial plane. CONCLUSIONS: Salter-Harris type II and triplane fractures have a high risk of periosteal entrapment especially in the anterolateral corner. Therefore, even without preoperative magnetic resonance imaging, surgical repositioning of entrapped periosteum should be considered after failed closed reduction. In cases of supinated foot injuries of type II or triplane fractures requiring surgical fixation, a metaphyseal fracture plane parallel to the oblique coronal plane connecting the medial and lateral malleoli may assist surgeons in achieving appropriate metaphyseal fixation. LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Giant occipital intradiploic epidermoid cyst associated with iatrogenic puncture.

The origin of cranial epidermoid cysts (EC) remains controversial, and although generally considered to be congenital, acquired origin has been reported. EC represent 0.2 to 1.8% of all brain tumours, and only one fourth are intradiploic in location. We report of a 44-year-old woman with a giant intradiploic EC of the occipital bone with intracranial extension confirmed on brain MRI. Three years previously, in the same location, she underwent resection of an intradermal melanocytic naevus of the skin under local anaesthesia with lidocaine infiltration of skin and periosteum. Brain CT scan performed at the time of naevus surgery because of associated headache did not show a lesion of the cranial vault. Iatrogenic epidermoid tumours are extremely rare, and although seeding of epidermal cells has been classically described only after lumbar puncture, the same mechanism may be involved after head injury, cranial surgery or cranial periosteal iatrogenic puncture.

Quadriceps tendon rupture and periosteal sleeve avulsion fracture of the proximal patella pole in an active adolescent.

A unique case of anterior knee pain in an active adolescent is described: a periosteal sleeve avulsion and quadriceps rupture in a young basketball player. The trauma mechanism was without any direct trauma on the knee. A review of overuse-related anterior knee pain in the young and active is presented. A quadriceps rupture with a periosteal sleeve avulsion fracture in an active adolescent is very rare. To our knowledge there are no similar cases described. This article presents a case of a 14-year-old adolescent boy who sustained a quadriceps rupture with a periosteal sleeve avulsion.