Tandem Reconstruction of the Femoral Diaphysis Using an Intercalary Prosthesis and a Fibular Free Flap.

BACKGROUND: Femoral diaphyseal reconstructions with metal prostheses have mediocre results because of high mechanical forces that result in eventual implant failure. Biological alternatives require prolonged restrictions on weight-bearing and have high rates of infection, nonunion, and fracture. A novel method of utilizing a vascularized fibula in combination with an intercalary prosthesis was developed to complement the immediate stability of the prosthesis with the long-term biological fixation of a vascularized fibular graft. METHODS: A prospectively maintained database was retrospectively reviewed to identify patients who underwent reconstruction of an oncological intercalary femoral defect using an intercalary prosthesis and an inline fibular free flap (FFF). They were compared with patients who underwent femoral reconstruction using an intercalary allograft and an FFF. RESULTS: Femoral reconstruction with an intercalary metal prosthesis and an FFF was performed in 8 patients, and reconstruction with an allograft and an FFF was performed in 16 patients. The mean follow-up was 5.3 years and 8.5 years, respectively (p = 0.02). In the bioprosthetic group, radiographic union of the fibula occurred in 7 (88%) of 8 patients, whereas in the allograft group, 13 (81%) of 16 patients had allograft union (p = 1.00) and all 16 patients had fibular union (p = 0.33). The mean time to fibular union in the bioprosthetic group was 9.0 months, whereas in the allograft group, the mean time to allograft union was 15.3 months (p = 0.03) and the mean time to fibular union was 12.5 months (p = 0.42). Unrestricted weight-bearing occurred at a mean of 3.7 months in the prosthesis group and 16.5 months in the allograft group (p < 0.01). Complications were observed in 2 (25%) of 8 patients in the prosthesis group and in 13 (81%) of 16 patients in the allograft group (p = 0.02). Neither chemotherapy nor radiation affected fibular or allograft union rates. Musculoskeletal Tumor Society scores did not differ significantly between the groups (mean, 26 versus 28; p = 0.10). CONCLUSIONS: Bioprosthetic intercalary femoral reconstruction with a metal prosthesis and an FFF resulted in earlier weight-bearing, a shorter time to union, fewer operations needed for union, and lower complication rates than reconstruction with an allograft and an FFF. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

What Is the Prosthetic Survival After Resection and Intercalary Endoprosthetic Reconstruction for Diaphyseal Bone Metastases of the Humerus and Femur?

BACKGROUND: Large metastatic lesions of the diaphysis can cause considerable pain and result in difficult surgical challenges. Resection and cemented intercalary endoprosthetic reconstruction offer one solution to the problem, but it is an extensive operation that might not be tolerated well by a debilitated patient. The risk of aseptic loosening and revision after intercalary endoprosthetic replacement has varied in previous reports, which have not examined the risk of revision in the context of patient survival. QUESTIONS/PURPOSES: (1) In a small case series from one institution, what is the survivorship of patients after cemented intercalary endoprosthetic replacement for diaphyseal metastasis, and what is the cumulative incidence of revision for any reason? (2) What are the complications associated with cemented intercalary reconstruction? (3) What is the functional outcome after the procedure as assessed by the MSTS93 score? METHODS: We retrospectively studied 19 patients with diaphyseal long bone metastases who were treated with resection and cemented intercalary endoprosthetic reconstruction by five participating surgeons at one referral center from 2006 to 2017. There were 11 men and eight women with a median age of 59 years (range 46 to 80 years). The minimum follow-up required for this series was 12 months; however, patients who reached an endpoint (death, radiographic loosening, or implant revision) before that time were included. One of these 19 patients was lost to follow-up but was not known to have died. The median follow-up was 24 months (range 0 to 116 months). Eight of the 19 patients presented with pathologic fractures. Ten of 19 lesions involved the femur, and nine of 19 were in the humerus. The most common pathologic finding was renal cell carcinoma (in 10 of 19). Survival estimates of the patients were calculated using the Kaplan-Meier method. A competing risks estimator was used to evaluate implant survival, using death of the patient as the competing risk. We also estimated the cumulative incidence of aseptic loosening in a competing risk analysis. Radiographs were analyzed for radiolucency at the bone-cement-implant interfaces, fracture, integrity of the cement mantle, and component position stability. Complications were assessed using record review that was performed by an individual who was not involved in the initial care of the patients. Functional outcomes were assessed using the MSTS93 scoring system. RESULTS: Patient survivorship was 68% (95% CI 50% to 93%) at 1 year, 53% (95% CI 34% to 81%) at 2 years, and 14% (95% CI 4% to 49%) at 5 years; the median patient survival time after reconstruction was 25 months (range 0 to 116 months). In the competing risk analysis, using death as the competing risk, the cumulative incidence of implant revision was 11% (95% CI 2% to 29%) at 1 year and 16% (95% CI 4% to 36%) at 5 years after surgery; however, the cumulative incidence of aseptic loosening (with death as a competing risk) was 22% (95% CI 6% to 43%) at 1 year and 33% (95% CI 13% to 55%) at 5 years after surgery. Other complications included one patient who died postoperatively of cardiac arrest, one patient with delayed wound healing, two patients with bone recurrence, and one patient who experienced local soft tissue recurrence that was excised without implant revision. Total MSTS93 scores improved from a mean of 12.6 ± 8.1 (42% ± 27%) preoperatively to 21.5 ± 5.0 (72% ± 17%) at 3 months postoperatively (p < 0.001) and 21.6 ± 8.5 (72% ± 28%) at 2 years postoperatively (p = 0.98; 3 months versus 2 years). CONCLUSION: Resection of diaphyseal metastases with intercalary reconstruction can provide stability and short-term improvement in function for patients with advanced metastatic disease and extensive cortical destruction. Aseptic loosening is a concern, particularly in the humerus; however, the competing risk analysis suggests the procedure is adequate for most patients, because many in this series died of disease without undergoing revision. LEVEL OF EVIDENCE: Level IV, therapeutic study .

Periosteal reaction-like lesions at the cranial aspect of the humeral diaphysis have a high prevalence in older, large breed dogs and may represent entheses of the superficial pectoral muscles.

Authors have commonly observed lamellar periosteal new bone formation at the cranial aspect of the humeral diaphysis in mediolateral radiographs of the humerus for large breed dogs with no evidence of pain or lameness. The aim of this retrospective, analytical study was to investigate the appearance and prevalence of "humeral periosteal reaction-like lesions" (HPRLL) in dogs and identify any predispositions. Mediolateral radiographs of humeri were evaluated and the presence and extent of "humeral periosteal reaction-like lesions" at the cranial aspect of the humerus were recorded. Macroscopic and histological examination of the humeri were performed for one dog with HPRLL. A total of 2877 mediolateral radiographs of 1727 dogs were included and focal or extended periosteal reaction-like lesions were found in 643 humeri of 387 dogs. Body weight ≥ 30 kg and age ≥ 7 years had a statistically significant, positive effect (P < 0.001) on the presence of HPRLL. German Shepherd dogs and Rottweilers were overrepresented in the group with HPRLL (P < 0.01). At the level of the HPRLL, the enthesis of the superficial pectoral muscles (M. pectoralis descendens and M. pectoralis transversus) to the Crista tuberculi majoris and Crista humeri were macroscopically and histologically identified. The authors propose that higher mechanical loads to the enthesis in large breed dogs may lead to physiological, age-related remodeling processes of the muscular attachment. The finding should not be confused with a pathological condition such as bone neoplasia.

Diaphyseal giant cell tumor with multiple relapses in a skeletally immature patient: a case report.

Giant cell tumor (GCT) is an aggressive osteolytic lesion mostly affecting the meta-epiphyses of long bones at skeletal maturity. Occurrence of the GCT in diaphysis is a rare entity in adult and exceptionally rare in pediatric population. This is the only third diaphyseal case reported in pediatric population. We report a case of recurrent diaphyseal GCT in a skeletally immature patient of 15-year-old male at the right radius after previous resection with plate and screw fixation. Upon optimal investigations, en-bloc resection of the tumor with radial resection and ulna centralization with wrist arthrodesis was done for a campanacci stage III GCT. The patient had an uneventful recovery without recurrence for 2 years and 2 months following surgery. The main challenge relies on accurate diagnosis due to uncommon location that hinders adequate treatment plan, therefore diagnosis should be solely based on histopathology findings.

Can fracture healing be accelerated by serum transfer in head trauma cases? An experimental head trauma model in rats.

OBJECTIVES: In this study, we aimed to investigate whether the positive union effect caused by head trauma could be transferred between individuals. MATERIALS AND METHODS: Seventy-two male rats with an average weight of 375 g were used in this study and divided into four groups including 18 in each group. Group 1 consisted of serum donor rats that were exposed to head trauma, while Group 2 consisted of study rats with long bone fractures that were given the serum obtained from the rats in Group 1, Group 3 included control rats with isolated long bone fractures, and Group 4 included control rats with both head trauma and long bone fractures. For radiological evaluation, the ratio of the width of the callus to the width of the neighboring diaphysis was considered as the callus-to-diaphyseal ratio in the study and control groups. Histopathological and radiological evaluations was made on Days 10, 20, and 30. RESULTS: In evaluation of the radiological data regarding the callus-to-diaphyseal ratio, Group 3 was found to have significantly lower radiological values than Group 4 on Day 10 (p=0.006). Group 2 had significantly higher values than Group 3 (p=0.02). On Day 20, Group 2 exhibited significantly higher radiological values than Group 3 (p=0.004), but lower than Group 4 (p=0.032). As for Day 30, Group 2 exhibited significantly higher radiological values than Group 3, but lower than Group 4 (p=0.001). In the evaluation of the Huo scores obtained for histopathological evaluation, there was no significant difference among the groups on Days 10, 20, and 30 (p=0.295, p=0.569, and p=0.729, respectively). CONCLUSION: Our study results suggest that the osteoinductive effect after head trauma can be transmitted between individuals by means of serum transfer.

Differences in subtrochanteric and diaphyseal atypical femoral fractures in a super-aging prefectural area: YamaCAFe Study.

INTRODUCTION: Atypical femoral fractures (AFFs) have been correlated with long-term use of bisphosphonates (BPs), glucocorticoids (GCs), and femoral geometry. We investigated the incidence and characteristics of subtrochanteric (ST) and diaphyseal (DP) AFFs in all institutes in a super-aging prefectural area. MATERIALS AND METHODS: We performed a blinded analysis of radiographic data in 87 patients with 98 AFFs in all institutes in Yamagata prefectural area from 2009 to 2014. Among the 98 AFFs, 57 AFFs comprising 11 ST fractures in 9 patients and 46 DP fractures in 41 patients with adequate medical records and X-rays were surveyed for time to bone healing and geometry. RESULTS: Of the 87 patients, 67 received BPs/denosumab (77%) and 10 received GCs (11%). Surgery was performed in 94 AFFs. Among 4 AFFs with conservative therapy, 3 required additional surgery. In univariate regression analyses for ST group versus DP group, male-to-female ratio was 2/7 versus 1/40, mean age at fracture was 58.2 (37-75) versus 78 (60-89) years, rheumatic diseases affected 55.5% (5/9) versus 4.9% (2/41), femoral lateral bowing angle was 1.7 (0-6) versus 11.8 (0.8-24)°, GC usage was 67% (6/9) versus 4.9% (2/41), and bone healing time was 12.1 (6-20) versus 8.1 (3-38) months (p < 0.05). In multivariate analyses, higher male-to-female ratio, younger age, greater proportion affected by rheumatic diseases, and higher GC usage remained significant (p < 0.05). CONCLUSIONS: The incidence of AFFs in our prefectural area was 1.43 cases/100,000 persons/year. This study suggests that the onset of ST AFFs have greater correlation with the worse bone quality, vice versa, the onset of DP AFFs correlated with the bone geometry. The developmental mechanisms of AFFs may differ significantly between ST and DP fractures.

Intramedullary injury combined with osteoporosis therapeutics regulates targeted local osteogenesis.

Bone marrow ablation prompts transient bone formation in nearly the entire medullary cavity before marrow regeneration occurs. Here, we establish a procedure to direct bone formation in a desired particular site within the medullary cavity for support of biomedical devices. Local intramedullary injury was performed in the tibiae of rats and parathyroid hormone (PTH), alendronate, or saline was administered. Newly generated bone in the medulla was assessed by micro-CT and histology. To evaluate the function of newly generated bone, animals received intramedullary injury in tibiae followed by daily PTH. At day-14, implants were placed in the endocortical bone and the bone response to the implants was assessed. The fate of newly generated bone was compared with and without implants. We found that neither intramedullary injury nor medication alone resulted in bone formation. However, when combined, substantial bone was generated locally inside the diaphyseal medulla. Newly formed bone disappeared without implant placement but was retained with implants. Bone was especially retained around and between the implants. This study found that local bone marrow disruption followed by PTH or alendronate generated substantial cancellous bone locally in the diaphyseal medulla. This approach offers promise as a tissue engineering tool in medicine and dentistry.

Changes in the intra- and peri-cellular sclerostin distribution in lacuno-canalicular system induced by mechanical unloading.

INTRODUCTION: Mechanical stimuli regulate Sclerostin (Scl), a negative regulator of bone formation, expression in osteocytes. However, the detailed Scl distribution in osteocytes in response to mechanical unloading remains unclear. MATERIALS AND METHODS: Twelve-week-old male rats were used. The sciatic and femoral nerves on the right side were excised as mechanical unloading treatment. A sham operation was performed on the left side. One week after neurotrauma, the bone density of the femora was evaluated by peripheral quantitative computed tomography, and immunofluorescence was performed in coronal sections of the femoral diaphysis. The mean fluorescence intensity and fluorescent profile of Scl from the marrow to the periosteal side were analyzed to estimate the Scl expression and determine to which side (marrow or periosteal) the Scl prefers to distribute in response to mechanical unloading. The most sensitive region indicated by the immunofluorescence results was further investigated by transmission electron microscopy (TEM) with immunogold staining to show the Scl expression changes in different subcellular structures. RESULTS: In femur distal metaphysis, neurotrauma-induced mechanical unloading significantly decreased the bone density, made the distribution of Scl closer to the marrow on the anterior and medial side, and increased the Scl expression only on the lateral side. TEM findings showed that only the expression of Scl in canaliculi was increased by mechanical unloading. CONCLUSIONS: Our results showed that even short-term mechanical unloading is enough to decrease bone density, and mechanical unloading not only regulated the Scl expression but also changed the Scl distribution in both the osteocyte network and subcellular structures.

Numerical investigation of mechanical behavior of human femoral diaphysis in normal and defective geometry: experimental evaluation.

Failure and major reoperation after internal fixation (IF) in mature femoral bones are common and proper selection of fixation method may reduce the rate of reoperations. Investigating the mechanical behavior of the human femoral diaphysis, this article studies effect of mechanical properties and geometry of the bone on selection of IF method. To this aim, we calculated the bone mineral density in human femurs, and then, using computed tomography scan, we obtained geometry and nonhomogeneous properties of the bone. Finite element (FE) models of osteotomised femurs were reinforced using four types of screws with a locking compression plate (LCP). We performed buckling and 4-point bending simulations, and results of these simulations represent critical buckling loads, maximum von Mises stresses, and strains around the screws and the central defect. To evaluate FE analysis, we employed the compressive experiments and compared load vs. displacement curves with FE results. Results corresponding to intact, osteotomised, and reinforced states are compared together, and the effect of cortical and unicortical screws in LCPs is studied. The FE results showed that application of identical prophylactic IF for two persons with identical injuries in the same conditions bring quite inverse results. As a consequence, evaluation of osteoporosis, elastic modulus, and morphometric data are required before fixation and screw selection. Besides, for short diaphysis, unicortical screws have maximum strengthening factor in bending. While for long samples, these types of screws can be the worst option, application of cortical screws results to maximum strength in comparison with other types.

Hypergravity as a gravitational therapy mitigates the effects of knee osteoarthritis on the musculoskeletal system in a murine model.

Insights into the effects of osteoarthritis (OA) and physical interventions on the musculoskeletal system are limited. Our goal was to analyze musculoskeletal changes in OA mice and test the efficacy of 8-week exposure to hypergravity, as a replacement of physical activity. 16-week-old male (C57BL/6J) mice allocated to sham control and OA groups not centrifuged (Ctrl 1g and OA 1g, respectively) or centrifuged at 2g acceleration (Ctrl 2g and OA 2g). OA 1g displayed decreased trabecular bone in the proximal tibia metaphysis and increased osteoclastic activity and local TNFα gene expression, all entirely prevented by 2g gravitational therapy. However, while cortical bone of tibia midshaft was preserved in OA 1g (vs. ctrl), it is thinner in OA 2g (vs. OA 1g). In the hind limb, OA at 1g increased fibers with lipid droplets by 48% in the tibialis anterior, a fact fully prevented by 2g. In Ctrl, 2g increased soleus, tibialis anterior and gastrocnemius masses. In the soleus of both Ctrl and OA, 2g induced larger fibers and a switch from type-II to type-I fiber. Catabolic (myostatin and its receptor activin RIIb and visfatine) and anabolic (FNDC5) genes dramatically increased in Ctrl 2g and OA 2g (p<0.01 vs 1g). Nevertheless, the overexpression of FNDC5 (and follistatine) was smaller in OA 2g than in Ctrl 2g. Thus, hypergravity in OA mice produced positive effects for trabecular bone and muscle typology, similar to resistance exercises, but negative effects for cortical bone.

Regresión de tumor pardo en adenoma paratiroideo / Brown tumor regression in parathyroid adenoma

No disponible

Animal models for studying metaphyseal bone fracture healing.

An estimated 2 million osteoporotic fractures occur annually in the US, resulting in a dramatic reduction in quality of life for affected patients and a high economic burden for society. Osteoporotic fractures are frequently located in metaphyseal bone regions. They are often associated with healing complications, because of the reduced healing capacity of the diseased bone tissue, the poor primary stability of the fracture fixation in the fragile bone, and the high frequency of comorbidities in these patients. Therefore, osteoporotic fractures require optimised treatment strategies to ensure proper bone healing. Preclinical animal models can help understanding of the underlying mechanisms and development of new therapies. However, whereas diaphyseal fracture models are widely available, appropriate animal models for metaphyseal fracture healing are scarce, although essential for translational research. This review covers large and small animal models for metaphyseal fracture healing. General requirements for suitable animal models are presented, as well as advantages and disadvantages of the current models. Furthermore, differences and similarities between metaphyseal and diaphyseal bone fracture healing are discussed. Both large- and small-animal models are available for studying metaphyseal fracture healing, which mainly differ in fracture location and geometry as well as stabilisation techniques. Most common used fracture sites are distal femur and proximal tibia. Each model found in the literature has certain advantages and disadvantages; however, many lack standardisation resulting in a high variability or poor mimicking of the clinical situation. Therefore, further refinement ofanimal models is needed especially to study osteoporotic metaphyseal fracture healing.

Effects of FK506 on the healing of diaphyseal, critical size defects in the rat femur.

There is much interest in understanding the influence of the immune system on bone healing, including a number of reports suggesting a beneficial effect of FK506 (tacrolimus) in this regard. The influence of FK506 in a rat, femoral, critical size defect was examined using locally implanted, recombinant, human (rh) BMP-2 and adenovirally-transduced, autologous, adipose-derived mesenchymal stromal cells (AD-MSCs) expressing BMP-2. FK506 was delivered systemically using an implanted osmotic pump. Empty defects and those implanted with unmodified AD-MSCs did not heal in the presence or absence of FK506. Defects treated with rhBMP-2 healed with a large callus containing thin cortices and wispy trabeculae; this, too, was unaffected by FK506. A third of defects implanted with adenovirally-transduced AD-MSCs healed, but this improved to 100 % in the presence of FK506. New bone formed in response to BMP-2 synthesised endogenously by the genetically modified cells had a slimmer callus than those healed by rhBMP-2, with improved cortication and advanced reconstitution of marrow. These results suggest that FK506 may have had little effect on the intrinsic biology of bone healing, but improved healing in response to adenovirally-transduced cells by inhibiting immune responses to the first-generation adenovirus used here. Because the genetically modified cells produced bone of higher quality at far lower doses of BMP-2, this approach should be explored in subsequent research.

Locking plate femur fracture repair in a juvenile Western chimpanzee (Pan troglodytes verus) in Sierra Leone.

This case reports the successful management of a traumatic diaphyseal femoral fracture in an infant Western chimpanzee (Pan troglodytes verus) from a rescue centre in Sierra Leone using a 2.4-mm intramedullary pin and two 2.7-mm String of Pearls™ locking plates. Locking plate use has not been previously described in chimpanzees.

Distal third femoral shaft fractures in school-aged children: A comparative study of elastic stable intramedullary nail and external fixator.

Internal fixation such as elastic stable intramedullary(ESIN) nail and submuscular plate (SMP) is gaining popularity for femoral shaft fractures in school-aged children. However, external fixation (ExFix) might be a valuable option for the distal third femoral shaft fractures, where the fracture heals rapidly, but it is crucial to avoid angular malunion. This study aims to compare the clinical outcomes, postoperative complications of distal third femoral shaft fractures in school-aged children treated by ESIN versus ExFix.Patients aged 5 to 11 years with distal third femoral shaft fractures treated at our institute from January 2014 to January 2016 were included and categorized into ESIN (n = 33) and ExFix (n = 38) group. The preoperative data, including baseline information of the patients, radiographic parameters, and type of surgical procedure, were collected from the hospital database, and postoperative data, including complications, were collected during the follow-up visit.In all, 33 patients (average, 8.0 ±â€Š2.1 years, male 20, female 13) in the ESIN group and 38 patients (average, 8.3 ±â€Š2.3 years, male 23, female 15) in the ExFix group were included in this study. There was significantly less operative time for the ExFix group (45.4 ±â€Š7.8 min) as compared to the ESIN group (57.8 ±â€Š11.3 min) (P < .01), reduced estimated blood loss (EBL) in the ExFix group (9.9 ±â€Š3.5) as compared to the ESIN group (16.4 ±â€Š6.5) (P < .01). As for the frequency of fluoroscopy, there was a significant difference between the ExFix group (13.9 ±â€Š2.4) and the ESIN group (15.5 ±â€Š3.2) (P = .02). The rate of major complications was not significantly different between the 2 groups (P = .19). The rate of implant irritation was significantly higher in the ExFix group (28/38, 73.7%) than the ESIN group (12/33, 36.4%) (P < .01). The rate of surgical site infection (SSI) is significantly higher in the ExFix group (18/38, 47.4%)) than the ESIN group (1/33, 3%) (P < .01). The rate of scar concern was significantly higher in the ExFix (9/38, 23.7%) than the ESIN (2/33, 6.1%), (P = .04). According to the Flynn scoring system, 30(90.9%) patients in the ESIN group and 24(89.5%) patients in the ExFix group were rated as excellent. None of the patients had poor outcomes.Both ESIN and ExFix produced satisfactory outcomes in distal third femoral shaft fractures. ExFix remains a viable choice for selected cases, especially in resource-challenged and austere settings.

Marrow adipose tissue in adolescent girls with obesity.

BACKGROUND: Marrow adipose tissue (MAT) is increasingly recognized as an active and dynamic endocrine organ that responds to changes in nutrition and environmental milieu. Compared to normal weight controls, adolescent girls with anorexia nervosa have higher MAT content, which is associated with impaired skeletal integrity, but data are limited regarding MAT content in adolescents with obesity and how this interacts with bone endpoints. OBJECTIVE: To evaluate (i) MAT content in adolescents with obesity compared to normal-weight controls, (ii) the association of MAT with bone endpoints, and (iii) whether these associations of MAT are affected by body weight. METHODS: We assessed MAT, bone endpoints, and body composition in 60 adolescent girls 14-21 years old: 45 with obesity (OB) and 15 normal-weight controls (NW-C). We used (i) DXA to assess areal bone mineral density (aBMD) at the lumbar spine and total hip, and total body fat and lean mass, (ii) proton magnetic resonance spectroscopy (1H-MRS) to assess MAT at the 4th lumbar vertebra and femur, and MRI to assess visceral (VAT) and subcutaneous adipose tissue (SAT), (iii) high resolution peripheral quantitative CT (HR-pQCT) to assess volumetric BMD (vBMD), (iv) individual trabeculae segmentation to evaluate trabecular bone (plate-rod morphology), and (v) finite element analysis to assess stiffness (a strength estimate) at the distal radius and tibia. RESULTS: Groups did not differ for age or height. Weight, BMI, and areal BMD Z-scores at all sites were higher in the OB group (p<0.0001). MAT was lower in OB at the femoral diaphysis (p= <0.0001) and the lumbar spine (p=0.0039). For the whole group, MAT at the lumbar spine and femoral diaphysis was inversely associated with BMI, total fat mass, lean mass, and VAT. Even after controlling for body weight, independent inverse associations were observed of femoral diaphyseal and lumbar MAT with total tibial vBMD, and of lumbar MAT with radial trabecular vBMD. CONCLUSION: Adolescent girls with obesity have lower MAT than normal-weight controls despite having an excess of total body fat. These findings confirm that MAT is regulated uniquely from other adipose depots in obesity. MAT was inversely associated with vBMD, emphasizing an inverse relationship between MAT and bone even in adolescent girls with obesity.

Efficacy of a Modified Scoring System to Facilitate Surgical Decision-making for Diaphyseal Malignancies: When is Devitalized Tumor-bearing Autograft of Value?

OBJECTIVES: To evaluate the validity of a modified scoring system (MSS) for inferring the bony quality of tumor-bearing diaphyses and predicting the risk of reconstructive failure after devitalized bone replantation (DBR). METHODS: In this retrospective cohort study, we reviewed the records of 30 patients surgically treated for diaphyseal malignancies between 1996 and 2015. There were 18 male and 12 female subjects; the average age was 34.0 ± 24.5 years (8-82 years). Tumor locations comprised the femur (21), the humerus (4), the tibia (3), the radius (1), and the fibula (1). Histological diagnoses included osteosarcoma (13), metastases (4), Ewing sarcoma (3), chondrosarcoma (3), malignant fibrohistiocytoma (2), periosteal osteosarcoma (1), Langerhans cell sarcoma (1), lymphoma (1), rhabdomyosarcoma (1), and malignant giant cell tumor (1). All primary tumors were rated as stage IIB. Twenty patients underwent DBR. Prosthetic procedures and segmental autografting/allografting were performed in 7 and 3 cases, respectively. MSS (comprising 5 elements: pain, tumor location, bone destruction, localized dimension, and longitudinal dimension) for each patient was calculated in accordance with their preoperative presentations. Outcome measurements included oncological results, outcomes of reconstructions, complications, and functional preservation, presented using the musculoskeletal tumor society (MSTS) scale. RESULTS: Follow up was available in 29 cases for an average duration of 61.0 ± 49.9 months (12-152 months). Infection occurred in 2 patients (6.9%), primary nonunion in 6 (27.3%), metastases in 9 (31.9%), recurrences in 4 (13.8%), and deaths in 7 (24.1%); 1 subject underwent amputation due to recurrence following endoprosthetic replacement (3.4%). In the DBR group, fractures occurred in 4 cases (21.1%) and nonunion in 5 (25%); internal fixation was related to nonunion (nails, 44.4% vs plates, 9.1%, P = 0.02). MSS was associated with fractures of devitalized autografts (11.0 ± 1.2 vs 8.3 ± 1.8, P = 0.01); the system was efficacious in predicting chances of fractures of these grafts (P = 0.02). MSS ≥ 10 (with false positive rate ≤ 6.7%) suggested increased fracture probability (≥22.7%) after DBR; therefore, 10 was considered a cutoff value. CONCLUSIONS: Diaphyseal malignancies with MSS ≥10 may contraindicate DBR for increased chances of reconstructive failure. In this situation, alternative procedures are advisable. Further investigations are warranted to assess the efficacy of MSS in implying the validity of DBR for diaphyseal malignancies.

Impact of Diaphyseal Cortical Thickness on Functional Outcomes After Arthroscopic Rotator Cuff Repair.

PURPOSE: To study the influence of combined cortical thickness (CCT) of the proximal humerus on arthroscopic rotator cuff tear repair outcomes. METHODS: The study included 210 patients who underwent arthroscopic repair of full-thickness supraspinatus tears. An independent reviewer measured CCT on preoperative radiographs, and patients were evaluated postoperatively at 3, 6, 12, and 24 months. Functional outcome was assessed with the Constant shoulder score (CSS), Oxford shoulder score (OSS), and University of California at Los Angeles Shoulder rating scale (UCLASS). The patients were divided based on CCT: ≥4 mm (higher CCT) and <4 mm (lower CCT). Univariate analysis and multivariate linear regressions were applied to study the effect of higher CCT on functional scores. RESULTS: At 6 months' follow-up, CSS and UCLASS were higher in the patients with higher CCT (mean ± standard deviation, 59 ± 17 vs 54 ± 14, P = .020; and 30 ± 5 vs 28 ± 5, P = .020, respectively). At 12 months' follow-up, CSS, UCLASS, and OSS were higher in the patients with higher CCT (71 ± 13 vs 65 ± 14, P = .002; 30 ± 5 vs 28 ± 5, P = .009; and 15 ± 6 vs 18 ± 7, P = .001, respectively). At 24 months' follow-up, CSS and OSS were higher in the patients with higher CCT (74 ± 11 vs 69 ± 13, P = .006; and 14 ± 4 vs 16 ± 8, P = .041, respectively). CONCLUSION: We conclude that although a higher CCT is not associated with clinically significant differences in functional outcomes, further studies examining postoperative imaging as well as perioperative optimization of bone mineral density may yield valuable results regarding the impact of CCT on cuff healing and functional outcomes. LEVEL OF EVIDENCE: III (retrospective comparative therapeutic trial).

Experimental Evaluation of the Properties of 3D Porous Bone Substitute Based on Calcium Phosphate on the Model of Monocortical Diaphysial Femur Defect in Rats.

A new alloplastic high-permeable material based on tricalcium phosphate with Kelvin architectonics created by stereolithographic 3D-printing was studied in vivo. A monocortical defect of the femur was modeled in rats and the material was implanted into the defect area. In 24 weeks, the animals were euthanized and histological examination of the defect area was performed. One femur fracture with fixator migration was recorded after implantation of the studied material and the reference chronOS synthetic material. The studied material demonstrated better osteoconductive properties then traditional osteoplastic material, which was seen from greater number of bone trabeculae and their area in the defect area.

Morphological profile of atypical femoral fractures: age-related changes to the cross-sectional geometry of the diaphysis.

The use of bisphosphonates for osteoporosis patients has markedly decreased the incidence of femoral neck or trochanteric fractures. However, anti-osteoporosis drugs have been reported to increase the incidence of atypical femoral fractures, which involve stress fractures in the subtrochanteric region or the proximal diaphysis. In this study, the morphological characteristics of the cortical bone in human femoral diaphysis samples were analyzed from individuals who lived before bisphosphonate drugs were available in Japan. A total of 90 right femoral bones were arbitrarily selected (46 males and 44 females) from modern Japanese skeletal specimens. Full-length images of these femurs were acquired using a computed tomography scanner. An image processing method for binarization was used to calculate the threshold values of individual bones for determining their contours. The range between the lower end of the lesser trochanter and the adductor tubercle of each femur was divided at regular intervals to obtain 10 planes. The mean value of cortical bone thickness, periosteal border length, and the cortical cross-sectional area was evaluated for all planes. Moreover, the ratio of the area of the cortical bone to the total area of cross-section at the mid-diaphysis was calculated. A comparison between males and females demonstrated that most females had lower cortical bone area ratios at the mid-diaphysis. The femoral outer shape did not differ markedly according to age or sex; however, substantial individual differences were observed in the shape of the inner surface of the cortical bone. The cortical bone thickness and the cross-sectional area decreased with age in the femoral diaphysis; furthermore, in females, the decrease was higher for the former than for the latter. This may be due to a compensatory increase in the circumference of the femoral diaphysis. In addition, in about half of the subjects there was a discrepancy between the region with maximal value of the cortical bone thickness and that of the total cross-sectional area. Biological responses to mechanical stresses to the femoral diaphysis are thought not to be uniform. Bisphosphonates inhibit bone resorption and may promote non-physiological bone remodeling. Thus, a nonhomogeneous decrease in cortical thickness may be related to the fracture occurrence in the femoral diaphysis in some cases. Thus, long-term administration of bisphosphonates in patients with morphological vulnerability in the femoral cortical bones may increase the occurrence of atypical femoral fractures.