Objectives. Prosthetic joint infection (PJI) is a devastating complication following total joint arthroplasty. Non-contact induction heating of metal implants is a new and emerging treatment for PJI. However, there may be concerns for potential tissue necrosis. It is thought that segmental induction heating can be used to control the thermal dose and to limit collateral thermal injury to the bone and surrounding tissues. The purpose of this study was to determine the thermal dose, for commonly used metal implants in orthopaedic surgery, at various distances from the heating centre (HC). Methods. Commonly used metal orthopaedic implants (hip stem, intramedullary nail, and locking compression plate (LCP)) were heated segmentally using an induction heater. The thermal dose was expressed in cumulative equivalent minutes at 43°C (CEM43) and measured with a thermal camera at several different distances from the HC. A value of 16 CEM43 was used as the threshold for thermal damage in bone. Results. Despite high thermal doses at the HC (7161 CEM43 to 66 640 CEM43), the thermal dose at various distances from the HC was lower than 16 CEM43 for the hip stem and nail. For the fracture plate without corresponding metal screws, doses higher than 16 CEM43 were measured up to 5 mm from the HC. Conclusion. Segmental induction heating concentrates the thermal dose at the targeted metal implant areas and minimizes collateral thermal injury by using the non-heated metal as a heat sink. Implant type and geometry are important factors to consider, as they influence dissipation of heat and associated collateral thermal injury. Cite this article: B. G. Pijls, I. M. J. G. Sanders, E. J. Kuijper, R. G. H. H. Nelissen. Segmental induction heating of orthopaedic metal implants. Bone Joint Res 2018;7:609–619. DOI: 10.1302/2046-3758.711.BJR-2018-0080.R1

Our aim was to assess the outcome of the treatment of Segmental fracture of the humerus in adult patients. From January 1994 to December 2003, 24 (17 females) consecutive adult patients with segmental humeral fractures were treated in our unit. Segmental fracture was defined as a two-level humeral fracture with at least one intermediate segment (AO type 12C). The mean age of the patients was 56.5 years(range 29–95) and the mean ISS was 14.1(range 9–29). The causes of injury included 8 vehicular accidents, 15 falls from heights, and 1 skiing injury. Thirteen patients had associated injuries. Three fractures were open (1 grade II, and 2 grade IIIA). At final follow up all patients were assessed in terms of radiological result and functional capacity (range of motion). The mean follow up was 36 months (range 24–60). There were 5 radial nerve palsies. Seven cases involved 4 fracture segments. The mean length of segment was 7 cm (range 5–16). All fractures but 5(20.8%) progressed to union (1 infected non-union, 1 hypertrophic after ex-fix, 1 atrophic after stabilization with rush pins, one was associated with failure of fixation proximally and required hemiarthroplasty). The mean number of procedures to achieve union in total was 1.6(range 1–3). There was one implant failure and one persistent non-union. At final follow up, the mean abduction was 1100 (900–1400) and the mean forward flexion was 1200 (1000–1500). Internal external rotation was 700 (50–90) and 250 (20–45). The risk of non-union is as high as 20.8 % and additional procedures often required to achieve union of the fragments. The method of stabilization depends on several factors including fracture configuration, the available bone stock and the surgeons’ expertise. Despite the severity of this injury a satisfactory outcome can be expected

INTRODUCTION. Standing spinal alignment has been the center of focus recently, particularly in the setting of adult spinal deformity. Humans spend approximately half of their waking life in a seated position. While lumbopelvic sagittal alignment has been shown to adapt from standing to sitting posture, segmental vertebral alignment of the entire spine is not yet fully understood, nor are the effects of DEGEN or DEFORMITY. Segmental spinal alignment between sitting and standing, and the effects of degeneration and deformity were analyzed. METHODS. Segmental spinal alignment and lumbopelvic alignment (pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), PI-LL, sacral slope) were analyzed. Lumbar spines were classified as NORMAL, DEGEN (at least one level of disc height loss >50%, facet arthropathy, or spondylolisthesis), or DEFORMITY (PI-LL mismatch>10°). Exclusion criteria included lumbar fusion/ankylosis, hip arthroplasty, and transitional lumbosacral anatomy. Independent samples t-tests analyzed lumbopelvic and segmental alignment between sitting and standing within groups. ANOVA assessed these differences between spine pathology groups. RESULTS. There were 183 NORMAL, 216 DEGEN and 92 DEFORMITY patients with significant differences in age, gender, and hip OA grades. After propensity matching for these factors, there were 56 patients in each group (age 63±14, 58% female) [Fig. 1]. Significant differences were noted between spinal pathology groups with regard to changes from standing to sitting alignment with regard to NORMAL vs DEGEN vs DEFORMITY groups in PT (13.93° vs −11.98° vs − 7.95°; p=0.024), LL (21.91° vs 17.45° vs 13.23°; p=0.002), PI-LL (−22.32° vs −17.28° vs −13.18°; p<0.001), SVA (−48.99° vs −29.98° vs −32.12°; p=0.002), and TPA(−16.35° vs −12.69° vs −9.64; p=0.001). TK (−2.08° vs −2.78° vs −2.00°, p=0.943) and CL (−3.84° vs −4.14° vs −3.57°, p=0.621) were not significantly different across spinal pathology groups [Fig. 2]. NORMAL patients had overall greater mobility in the lower lumbar spine from standing to sitting compared to DEGEN and DEFORMITY patients. L4-L5 (7.50° vs 5.23° vs 4.74°, p=0.012) and L5-S1 (6.96° vs 5.28° and 3.69°, p=0.027). There were no significant differences in change in alignment from standing to sitting at the upper lumbar levels or lower thoracic levels between the three groups [Fig. 3]. CONCLUSION. The lower lumbar spine provides the greatest sitting to standing change in lumbopelvic alignment in normal patients. Degeneration and deformity of the spine significantly reduces the mobility of the lower lumbar spine and PT. With lumbar spine degeneration and flatback deformity, relatively more alignment change occurs at the upper lumbar spine and thoracolumbar junction

Introduction. Segmental bone defect is a challenging problem. We report our experience of bone transport by hexapod external fixator in patients with segmental defects if the tibia. Method. We report herein 15 patients with segmental bone defect of tibia who completed their treatment protocol. All patients were treated had bone transport with Taylor Spatial Frame from 2012 to 2017. All were treated by the senior author NH. Parameters measured included age, sex, diabetes, smoking, diagnosis, method of fixation prior to treatment use of a free flap, bone defect size, frame-time, external fixation index. Results. Mean age at the time of frame application was 42.7 years. Mean follow-up after frame removal was 23.7 months. Three were diabetic, one smoked and one quit smoking during treatment. Seven had Gustilo-Anderson 3B (47%) and 5 Gustilo-Anderson 3A (33%) open fractures. Three (20%) had closed fractures. Nine (60%) had internal fixation with plate in eight and IM nail in one. Ten patients (67%) had soft tissue defect that required a free flap in seven, local flap in two and skin graft in one. Mean transport was 62 mm. Mean external fixator time and latency were 350.1 and 12 days, respectively. Mean External fixator, distraction and maturation indices were 2.1, 0.52 and 1.43 month per centimeter, respectively. Ten Extra- procedures were required in 7 patients. There were no docking site procedures, non-union of regenerate, adjunctive stabilization after frame removal, recurrence of bone infection and recurrence of deformity. Conclusions. Segmental resection and transport by TSF is an effective method to achieve length, alignment and eradicate infection. Although our cohort had longer external fixator indices than similar studies, the complication rate was low

Aim. Segmental bone defects following osteomyelitis in pediatric age group may require specifically designed surgical options. Clinical and radiographic elements dictate the option. Different elements play a role on the surgeon's choice. Among them, the size of the defect, the size and the quality of the bone stock available, the status of the skin envelope, the involvement of the adjacent joint. When conditions occur, vascularized fibula flap may represent a solution in managing defects of the long bones even during the early years of life. Method. A retrospective study, covering the period between October 2013 and September 2015, was done. Fourteen patients, nine males, five females, aged 2–13 years, with mean skeletal defect of 8.6 cm (range, 5 to 14 cm), were treated; the mean graft length was of 8.3 cm. The bones involved were femur (4), radius (4), tibia (3) and humerus (3). In 5 cases fibula with its epiphysis was used, in 5 cases the flap was osteocutaneous and in the remaining 4 cases only fibula shaft was utilized. After an average time of 8 months from eradication of infection, the procedure was carried out and the flap was stabilized with external fixators, Kirschner's wires or mini-plate. No graft augmentation was used. Results. Total limb reconstruction was achieved in 13 of 14 cases. The average integration period was 3.5 months. The mean follow-up period was 20.7 months (range 22–43). Mean time for full weight bearing in reconstructed lower limb was 5.8 months. All patients were walking pain-free and none with a supportive device. The fibular flap with epiphysis had good functional outcomes. A few early and delayed complications were observed. Lengthening through one graft on the forearm was achieved and the radial length restored. Conclusions. In low resource setting, provided that the technical skills and the right equipment are available, reconstruction of segmental bone defects secondary to hematogenous osteomyelitis in children using vascularized fibula flap is a viable option that salvages and restores limb function

Segmental bone transport (SBT) using an external fixator is currently a standard treatment for large-diameter bone defects at the donor site with low morbidity. However, long-term application of the device is needed for bone healing. In addition, patients who received SBT treatment sometimes fail to show bone repair and union at the docking site, and require secondary surgery. The objective of this study was to investigate whether a single injection of recombinant human bone morphogenetic protein 2 (rhBMP-2)-loaded artificial collagen-like peptide gel (rhBMP-2/ACG) accelerates consolidation and bone union at the docking site in a mouse SBT model. Six-month-old C57BL/6J mice were reconstructed by SBT with external fixator that has transport unit, and a 2.0-mm bone defect was created in the right femur. Mice were divided randomly into four treatment groups with eight mice in each group, Group CONT (immobile control), Group 0.2mm/d, Group 1.0mm/d, and Group BMP-2. Mice in Group 0.2mm/d and 1.0mm/d, bone segment was moved 0.2 mm per day for 10 days and 1.0 mm per day for 2 days, respectively. Mice in Group BMP-2 received an injection of 2.0 μg of rhBMP-2 dissolved in ACG into the bone defect site immediately after the defect-creating surgery and the bone segment was moved 1.0 mm/day for 2 days. All animals were sacrificed at eight weeks after surgery. Consolidation at bone defect site and bone union at docking site were evaluated radiologically and histologically. At the bone defect site, seven of eight mice in Group 0.2mm/d and two of eight mice in Group 1.0mm/d showed bone union. In contrast, all mice in Group CONT showed non-union at the bone defect site. At the docking site, four of eight mice in Group 0.2 mm/d and three of eight mice in Group 1.0 mm/d showed non-union. Meanwhile, all mice in Group BMP-2 showed bone union at the bone defect and docking sites. Bone volume and bone mineral content were significantly higher in Group 0.2mm/d and Group BMP-2 than in Group CONT. HE staining of tissue from Group 0.2mm/d and Group BMP-2 showed large amounts of longitudinal trabecular bone and regenerative new bone at eight weeks after surgery at the bone defect site. Meanwhile, in Group CONT and Group 1.0mm/d, maturation of regenerative bone at the bone defect site was poor. Differences between groups were analyzed using one-way ANOVA and a subsequent Bonferroni's post-hoc comparisons test. P < 0.05 was considered significant. rhBMP-2/ACG combined with SBT may be effective for enhancing bone healing in large bone defects without the need for secondary procedures

Introduction. Segmental tibia fractures are high-energy injuries that are difficult to treat. We report on the use of the Ilizarov Method to treat 40 consecutive AO 4.2C (35) and AO 4.2B3 (5) fractures by a single surgeon. Fractures with bone loss requiring transport were excluded, as were fractures initially treated with nail or plate. Patients: 28 adult males, 12 adult females, mean age 43. The most common mechanism of injury was RTA (50%). Twelve patients (30%) had associated injuries. Nineteen (48%) fractures were open (6 Gustillo-Anderson 3A, 13 Gustillo-Anderson 3B) and 21 closed; 24 (60%) had temporary monolateral external fixation before definitive treatment. The mean time from injury to definitive Ilizarov frame was 8 days. Results. 37 (93%) healed without the need for any bone-stimulating procedure. The other 3 healed with further procedures and a second frame. There were no amputations and no deep infections. None required intervention for malunion. The total time to healing was calculated from date of injury to frame removal. Open fractures (mean 214 days, median 182) took longer to heal than closed fractures (mean 177 days, median 177). Minor complications included snapped wires (2) and minor pinsite infections treated with oral antibiotics (9). Clinical scores were available for 25 of the 40 patients (median 55 months post-injury) with ‘Good’ Olerud and Molander ankle scores (median 80), ‘Excellent’ Lysholm knee scores (median 99), median Tegner activity score of 4 (comparable to ‘moderately heavy labour’) and above mean population SF12 scores (mean PCS 52, mean MCS 54). Conclusion. The Ilizarov Method is a very safe technique to successfully treat segmental tibia fractures with high union rates (93%)

Introduction. Segmental tibia fractures are high-energy injuries that are difficult to treat. We report on the use of the Ilizarov Method to treat 40 consecutive AO42C (35) and AO42B3 (5) fractures by a single surgeon. Fractures with bone loss requiring transport were excluded, as were fractures initially treated with nail or plate. Patients. 28 adult males, 12 adult females, average age 43. The most common mechanism of injury was RTA (50%). 12 (30%) had associated injuries. 19 (48%) fractures were open (6 3A, 13 3B) and 21 closed. 24 (60%) had temporary monolateral external fixation before definitive treatment. The mean time from injury to definitive Ilizarov frame was 8 days. Results. 37 (93%) healed without the need for any bone-stimulating procedure. The 3 non-unions subsequently healed with a second frame. There were no amputations and no deep infections. All injuries healed within ten degrees of anatomical alignment radiologically. The total time to healing was calculated from date of injury to frame removal. Open fractures (mean 214 days, median 182) took longer to heal than closed fractures (mean 177 days, median 177). Minor complications included snapped wires (2) and minor pinsite infections treated with oral antibiotics (9). Conclusion. The Ilizarov Method is a very safe technique to successfully treat segmental tibia fractures with high union rates (93%)

Study Design: Retrospective study. Objective: To describe a modified cervico-thoracic extension osteotomy and evaluate clinical & radiographic outcomes. Subjects: 10 patients with fixed cervico-thoracic kyphosis, average age 56 years, minimum 12 months follow-up. Three patients had psoriatic spondyloarthropathy, Three patients had previous lumbar osteotomies. Technique: General anaesthesia and SSEP spinal cord monitoring was used. Complete laminectomy of C7, hemilaminectomy of C6 and T1, plus pedicle subtraction osteotomy and decancellisation of C7 was performed. Upon completion of the osteotomy, controlled halo manipulation allowed closure of the osteotomy: the pivot point being the anterior longitudinal ligament. Segmental fixation with lateral mass and pedicle screws plus bone graft was then added. All patients were immobilised for three months in halo-jacket. Results: Restoration of normal forward gaze was achieved in all patients. Mean preoperative kyphosis of 17 degrees was corrected to lordosis of 36 degrees (mean total correction 53 degrees). No spinal cord injuries or permanent nerve root palsies occurred. Three patients had mild sensory radiculopathies lasting a few weeks. No loss of correction, no pseudarthrosis, one patient had 50% anterior subluxation that later united. Two deep infections were successfully treated with wound washout and antibiotics. Conclusions: Cervico-thoracic osteotomy in ankylosing spondylitis continues to be challenging and hazardous. C7 decancellisation and extension osteotomy supplemented with segmental internal fixation provides immediate spinal stability, reduces sagittal spinal translation and associated high risk of neurological injury, whilst maintaining correction until bony union

Summary Statement. Bio-impedance analysis (BIA) provides a convenient method for the estimation of whole body and segmental measurement of skeletal muscle mass (SMM). BIA-measured SMM parameters may be effectively used for the normalisation of muscle strength and removing body-size dependence. Introduction. Despite an increasing interest in using bio-impedance analysis (BIA) for the estimation of segmental skeletal muscle mass (SMM); existing data is sparse. On the other hand, there is a need for better understanding of the influence of SMM on gender-related differences in muscle strength. Using BIA technique, this study aimed to measure the SMM, determine its correlation with muscle strength, and examine its relation with gender-related differences in muscle strength. Patients and Methods. Segmental and whole body SMM (3-segment electrode configuration) and maximum voluntary contraction in five distinct shoulder planes (forward flexion, abduction in scapular plane, abduction in coronal plane, and internal- and external rotation) were measured in 45 healthy participants (22 males, 23 females) with a mean age of 30.3 years. Independent t-tests and Pearson Correlation test were applied for comparative and correlational analysis, respectively. Results. All muscle-related parameters including muscle volume, SMM, and SMM index were significantly different between men and women. There was a significant gender-related difference in the absolute shoulder strength but not after normalisation to SMM. A strong correlation was found between strength and SMM and in-between strength measurements. Conclusion. BIA provided a convenient method for SMM estimation. SMM parameters may be effectively used for strength normalisation allowing comparisons of individuals with differing body masses. Strong correlations between SMM and muscle strength supported the use of BIA in assessing muscle size-strength relations and its applicability in muscle function assessments

Segmental bone defects with complex fractures or chronic infections comprise a very special subset of patients. Modular endoprosthetic reconstruction is an operative solution. Without reconstruction amputation/disarticulation is the likely outcome. Aim of the study was to analyse preliminary results of modular endoprosthetic reconstruction in nonneoplastic limb salvage. 11 patients(9 – distal femoral replacement, 2 – total femoral replacement) underwent salvage reconstruction between January 2005 and March 2008 for chronic periprosthetic infections(6 – single stage revision; 2 – two stage revision) and complex periprosthetic fractures(3) with segmental bone defects. Microbiological and haematological evidence of infection was confirmed in the infection group and treated with concomitant community based antibiotic therapy as per guidance from specialist team. The mean age and follow up were 74.2 years and 27.5 months respectively. No intraoperative complications identified. Average post operative mobilisation was with frame at 5 days, 2 sticks at 2 weeks. 1 patient required plastic surgical intervention at index operation. 1 patient had recurrence of infection. Radiographs at 6, 12 & 24 months showed no changes from immediate post-op. Microbiological and haematological evidence of infection eradication was considered as successful treatment. Knee range of movements averaged full extension to 95 degrees. Oxford knee scores showed maximal improvement in the single stage revision group. We conclude that salvage endoprosthetic reconstruction has provided an oppourtunity to avoid amputation. A significant improvement in overall range of motion, knee scores, pain relief and stability was achieved in this highly complex subset of patients. Multidisciplinary support from plastic surgeons and specialist microbiologists is essential

Purpose: To assess the usefulness of Bone Transport and other “compression-distraction” systems for the treatment of Segmental Bone Defects (SBD) in patients younger than 16 years-old. Patients and methods: This series includes 18 patients (12 boys, 6 girls) with SBD of the following etiologies: Post-traumatic defects with/without sepsis (14 cases) and post-resection defects (3 Congenital Pseudoartrosis of the Tibia -CPT- and 1 Aneurismal Bone Cyst). The age of the patients ranged from 8 to 16 years and the length of the defect from 5 cm to 13 cm except for one case (23 cm). The defect was located in the tibia in 14 cases and in the femur in four. Nine patients (the longest defects) were treated by conventional Bone Transport whereas other compression-distraction techniques were used in the remaining. Monolateral frames were used in all cases. All but one of the post-traumatic cases had additional injuries and in four occasions one of the joints adjacent to the defect was involved. Results: All cases healed, 6 with only one operation and 12 with more than one procedure. Healing time depended upon the length of the defect, age of the patient, etiology and occurrence of complications. Healing index also varied mainly depending on the etiology (CPT cases were slower) ranging form 1.5 to 0.7 months/cm. Bone graft at the compression site was used in 9 cases. Radiologically the most striking feature was the very early tubulization of the reconstructed segment along with the quick healing of the SBD. The most frequent complication was pin tract infection (37%), one case needing change of pins. Fracture at the pin site was seen in two cases. Functional results were closely related to: a. The healing of the defect and b. The existence of injuries to the joints adjacent to the defect. With a minimum follow-up of 18 months there were 2 poor functional results due to an avascular necrosis of the dome of the talus (talus neck fracture). Conclusion: These techniques are very useful in selected cases of large SBD in young patients. They have shown low morbidity, quick healing and, above all, very good remodeling potential. Associated injuries play a very important role in the final outcome of the treatment

Introduction We review our experience with the use of plate and screw (C1 lateral mass and C2 pedicle) method of fixation in the treatment of 300 patients with disorders of the craniovertebral junction during a 17-year period at our center. We previously described this method of fixation in 1994. Methods Between 1988 and 2004, 250 patients with atlantoaxial instability were treated with the use of a plate and screw method of fixation at our institution. The various aetiologies of atlantoaxial instability were congenital, trauma and rheumatoid arthritis. All patients had mobile, completely reducible atlantoaxial subluxation. The male: female ratio was 3:1. C1 lateral mass screw and C2 pedicle screw were anchored to a plate bilaterally. For 3 months postoperatively, a hard cervical collar was used. The mean follow-up period was 42 months (range, 4 mo–17 yr). Recently, we have modified the technique by distracting the lateral facet joints, placing a cage bilaterally and then performing the lateral mass fixation for a subgroup of 50 patients with either fixed atlantoaxial joint subluxation or basilar invagination. Results Three patients died in the postoperative phase. Successful stabilization of the atlantoaxial region was documented with dynamic radiography in the other patients. In one patient, one screw was found to be broken 18 months after surgery; however, firm bony fusion was documented in this patient. There were no neurological, vascular, or infective complications. Discussion Segmental fixation of lateral masses with plate and screw method of fixation with the use of intra-articular bone grafts in patients with atlantoaxial instability yielded a 100% fusion rate with a low incidence of complications. Direct application of screws into the thick and large cortico-cancellous lateral masses of atlas and axis provides a biomechanically strong fixation of the region

Nonunions and segmental bone defects associated with infection are challenging problems faced by the orthopaedic surgeon. Antibiotic cement-coated (ACC) interlocking nails, prepared in the operating theatre using nails and materials generally available, can be used to treat these conditions. Two different types of moulds can be used (reusable or disposable). Materials and Methods: The infected nonunion/segmental bone defect was treated by débridement followed by ACC nailing in 52 patients (12 female, 40 male, age range 16–86 years). Other procedures for deformity correction, bone defect etc were carried out simultaneously as indicated. Infected nonunion was seen in 34 patients, 1 was an acute fracture after external fixator. Segmental defect in the bone of 1 to 30 cm was seen in 17 patients. Anatomical sites included Femur (13), Tibia (11), Knee (12) and ankle (16). Results: Limb salvage was achieved in 96% and amputation in 2 patients. Bony union was achieved in 41 of 49 patients (84%). In 3 patients (15%), control of infection was achieved with stable nonunion (1 patient) and stable nonunion with cement spacer (2 patients). Control of infection was achieved in 85%. Single procedure achieved this goal in 73%. Cement nail de-bonding occurred during removal in 9 patients and during insertion in 1 patient. The average follow-up was 16 months (1 to 60 m). Conclusion: Dual goals of control of infection as well as stability to promote union can be achieved using this technique. Although useful for all infected nonunions, this technique is particularly useful for patients who are not ideal candidates for external fixators or those who do not want an external fixator

Common cell based strategies for treating bone defects require time-consuming and expensive isolation and expansion of autologous cells. We developed a novel expedited technology creating gene activated muscle grafts. We hypothesized that BMP-2 activated muscle grafts provide healing capabilities comparable to autologous bone grafting, the clinical gold standard. Two male, syngeneic Fischer 344 rats served as tissue donors. Muscle tissue was harvested from hind limbs and incubated with an adenoviral vector carrying the cDNA encoding BMP-2. Bone tissue was harvested from the iliac crest. Segmental bone defects were created in the right femora of 12 rats and were filled with either BMP-2 activated muscle tissue or bone grafts. After 8 weeks, femora were evaluated by radiographs, microCT, and biomechanical tests. BMP-2 activated muscle grafts and autologous bone grafts resulted in complete mineralization and healing, as documented by radiographs and microCT. Bone volume in the muscle graft defects (33+/-12mm3) was similar to autologous bone graft defects (39+/-5mm3). Torque at failure of the two groups was statistically indistinguishable (240+/-115 Nmm vs. 232+/-108Nmm). In previous experiments we demonstrated that the large segmental defect model in this study will not heal with either empty defects or non-activated muscle grafts. Our findings therefore demonstrate that BMP-2 gene activation of muscle tissue effectively stimulates defect healing similar to autologous bone grafts

Aim: Bone grafts and bone graft substitutes are often used at radical surgical procedures such as; trauma, congenital anomalies, tumor surgery, bone infections, revision arthroplasty surgery, spinal surgery. However autograft and allograft bone are frequently used, they have some limitations. ABM/P-15 (Pepgen P-15) is a combination of anorganic bovine derived hydroxyapa-tite matrix coupled with a synthetic-cell binding peptide (P-15). This tissue engineered particulate bone replacement graft has been established for the treatment of periodontal osseous defects. The aim of this study is to determine the effect of ABM/P-15 on the healing of a critical sized segmental defect in rat radius. Methods: 36 Wistar rats were used at this study. A critical sized segmental defect was created in each rat radius. 13 defects were filled with ABM/P-15 Flow (putty form), 12 defects were filled with ABM/P-15, and 11 defects were used as a control group. The rats were killed at 10 weeks. The healing of defects was evaluated with radiographic and histological studies. Results: The use of ABM/P-15 and ABM/P-15 Flow were demonstrated improved healing of segmental bone defects in rat radius on radiographic and histological studies compared with control group. Statistical evaluation showed that there were significant differences between control sites, and sites treated with P-15 and P-15 Flow (p< 0.005). The highest radiological and histological grades were achieved by P-15. Osteogenic proliferation was seen at the P-15 group more than P-15 flow. Conclusion: Segmental cortical bone defects may be treated with ABM/P-15 instead of bone allografts, and autografts. According to the radiologic and histological parameters measured in this study, the implantation of ABM/P-15 resulted in optimum healing of the segmental cortical bone defects

Background: To determine whether the operation of LSD destabilizes the lumbar spine and leads to an increase in any pre-existing scoliosis or spondylolisthesis. Lumbar spondylosis, which commonly includes a degenerative listhesis and a scoliosis, is the commonest cause for stenosis in the lumbar spine. The standard operation for spinal stenosis remains a laminectomy with fixation and fusion in the presence of possible instability. The laminectomy, however, destabilises the spine and the instrumented fusion makes it a much bigger operation in patients often not best placed to cope with it. The more limited operation of LSD, which has previously been reported to this society, avoids a simultaneous fusion or instrumentation and has been shown to give long term symptomatic relief (. 1. ) Its possible effect on the stability of the spine has not previously been reviewed. Methods: A retrospective clinical and radiological review of consecutive patients operated on for degenerative spinal canal stenosis with either a pre-existing scoliosis or degenerative listhesis or both. Sixty-one patients (44 female and 17 male) with a mean age at operation of 72.8ys (range: 54–85). Pre-operatively 35patients (57%) had a degenerative listhesis, 14 patients (23%) a lumbar scoliosis and 12 (20%) had both. The mean postoperative follow-up was three years (range from one to fourteen years). Results: None of the 47 patients with a preoperative degenerative spondylolisthesis had any change in grade of the listhesis. Also no patient developed a new spondylolisthesis. Of the 26 patients with a preoperative scoliosis, 10 progressed by a mean of 4.9° (range 2°–15°). Conclusion: The results show that the operation of LSD was not associated with the development of a spondylolisthesis or a further progression of a pre-existing listhesis, and no patient developed a scoliosis. In those who had a scoliosis pre-operatively, 38% progressed and this only to a degree which we believe falls within the natural progression to be expected in such a group of patients. We believe these results support the view that the operation of Limited Segmental Decompression for spinal stenosis does not significantly destabilize the spine, even in a group that would appear most vulnerable, and as such there is no indication in such cases to consider a simultaneous instrumentation and fusion

Aim

infected segmental bone defect (ISBD) is frequent in developing countries. The aim of this study was to assess the efficacy of the Masquelet technique in the treatment of ISBD in a low-resource setting.

Purpose: One of the most difficult challenges for orthopaedic surgeons is the management of bone loss resulting in a segmental bone defect. Segmental bone defects are ubiquitously difficult to treat, require multi-phase surgery and have frequent complications. A promising new strategy involves combining tissue engineering techniques with the delivery of biologically active proteins to facilitate bone regeneration. The purpose of this study is twofold:. First, to investigate whether a cylindrical, biodegradable load-bearing scaffold, stabilized with an intramedullary (IM) nail, will facilitate early weight bearing in a critical sized canine defect model. The second objective is to investigate if rhBMP-2, transported by the biodegradable carrier, will enhance bone formation and healing across a critical sized canine defect. Method: A critical size defect of 3 cm was created in the canine tibia by osteotomy. A cylindrical, biodegradable scaffold of (poly) propylene fumarate was inserted into the defect and the tibia was stabilized with a locked intramedullary nail. Half of the scaffolds were impregnated with 300μg rhBMP-2 and half remained as controls. The animals were allowed immediate weight bearing post-operatively. X-rays were obtained post-operatively and at weeks 1, 2, 3, 6, 12, 18, and 24. X-rays were assessed for loss of height, integrity of the scaffold, and presence of bridging callous formation. Results: The animals that received scaffolds treated with rhBMP-2 showed abundant callus formation on X-ray. Partial bridging callus formation in this group was seen at 3 weeks. Complete bridging callus (bridging on 4 cortices) was observed by 6 weeks. These specimens maintained height of the defect and overall length of the tibia. Controls demonstrated minimal callus formation at all time points. By 3 weeks significant loss of defect height was observed. By 6 weeks failure of hardware (breakage of interlocking screws and/or screw loosening) was evident. Conclusion: This study shows that biodegradable scaffolds, treated with rhBMP-2 and implanted in a critical sized defect facilitate bridging callus formation and healing across the defect. This data indicates that biodegradable scaffolds made of (poly) propylene fumarate are suitable carriers for rhBMP-2 while providing initial structural support for weight bearing

Bone impaction grafting of the femur is associated with more complications when segmental defects are present. The effect of segmental defect repair on initial stem stability was studied in an in vitro study with fresh frozen goat femora. A standardized medial segmental defect was reconstructed using a cortical strut or a metal mesh. As controls we used intact femora and femora with a non-reconstructed defect. In all four groups impacted bone grafting was performed in combination with a cemented Exeter stem. Each group contained five femora. Reconstructions were dynamically loaded up to 1500N. Migration was measured with Roentgen Stereo-photogrammetric Analysis. All cases with a non-reconstructed segmental defect failed into excessive varus rotation. None of the femora with a reconstructed defect failed. Cortical struts and metal meshes were equally effective in creating a stable stem construction (varus rotation 2.89±2.27 and 2.27±0.57, respectively). Reconstructions with a metal mesh were more reproducible, although the obtained stability was significantly lower (p< 0.01) when compared to impaction grafting in an intact femur (varus rotation 0.58±0.36). Besides, structural grafts may negatively influence the revascularization of the underlying impacted grafts in contrast to an open wire mesh. So, an in vivo study of 12 goats was done. A standardized medial wall defect was reconstructed with a strut or a mesh in six goats per group. In all femora impaction grafting was performed in combination with a cemented Exeter stem. After six weeks the femora were harvested. A high rate of peri-prosthetic fractures was found (43% and 29% for the strut and mesh groups, respectively). Histological and micro-radiological examination showed different revascularization patterns for both reconstruction techniques. In the strut group revascularized graft was found at the edges of the defect. In the mesh group fibrous tissue and blood vessels penetrated through the mesh and a superficial zone of revascularized grafts was found. Segmental defect reconstruction with a strut reduced the amount of revascularized grafts medially behind the strut (p=0.004). This may interfere with the stability of the stem in the first period after surgery and the incorporation of the impacted grafts on the long-term. We would recommend segmental defect reconstruction with a mesh. A regime of unloading and long-stem prostheses should be used, irrespective of the reconstruction technique