Management of post-infection forearm defect non-unions following the “Road-to-Union” protocol: technical note and case series

What's New in Limb Lengthening and Deformity Correction.

The Limb Lengthening and Reconstruction Society (LLRS) celebrated its 28th year as an orthopaedic subspecialty, with a combined meeting with the Pediatric Orthopaedic Society of North America (POSNA) at the 2019 American Academy of Orthopaedic Surgeons (AAOS) meeting in Las Vegas. The LLRS 28th Annual Scientific Meeting was held on July 19 and 20, 2019, in Boston, Massachusetts, featuring papers and workshops from around the world. A diverse subspecialty society, we overlap with trauma, pediatric, foot and ankle, sports, arthroplasty, and oncologic orthopaedic surgeons in the diagnosis and treatment of deformities of length, alignment, contracture, nonunion, and bone healing. The purpose of this update was to summarize the important articles with regard to these subjects published since 2018. Guided Growth The technique of temporary, asymmetric growth plate tethering continues to be a successful method of deformity correction in growing children. The concept, known as guided growth, was developed by Dr. Peter Stevens, using a small, 2-hole plate to span the growth plate on 1 side, allowing the opposite side to grow unresisted, and thereby correcting angular deformity without osteotomy. The screws within the plate provide an articulation, with the apex of the correction occurring at the perichondrial ring. A multinational retrospective study described results of guided growth in 537 children with 967 physes treated1. Distal femoral and proximal tibial correction rates were similar, averaging 0.77° per month for the distal part of the femur and 0.79° for the proximal part of the tibia, despite the commonly held opinion that the femur corrects faster than the tibia. Patients with >3 years of growth remaining had a better quality of correction. Infection was uncommon, occurring in 1.78% of patients. Seven of the 8 infections occurred at the upper medial part of the tibia. The study was unable to correlate the effect of body weight on the result, nor did it assess the incidence of rebound deformity. A modified guided growth technique has been previously advocated for only removing the metaphyseal screw and leaving the plate and epiphyseal screw in place once a correction is complete. Thus, in the event that a deformity recurs, a simpler procedure to reinsert a single screw could be performed. A study by Keshet et al. refuted this practice2, as they observed permanent bar formation in 2 of 55 cases using the technique. They also observed that only 12 of their 55 patients required reinsertion of the metaphyseal screw and that 9 of those actually required plate repositioning. Anterior guided growth of the distal part of the femur to treat fixed knee flexion contracture in cerebral palsy has been reported to have favorable results, provided that implants are placed sufficiently anterior and adequate growth remains3. Congenital Pseudarthrosis of the Tibia Congenital pseudarthrosis of the tibia remains a challenge for the orthopaedic surgeon. Richards and Anderson4 reported using bone morphogenetic protein (BMP)-2 without deleterious effects in 21 children with congenital pseudarthrosis. They applied a single sponge around an autologous cancellous bone graft with intramedullary pinning that crossed the ankle joint. This technique seemed to shorten the time to union, but did not eliminate nonunion or refracture, the latter occurring in 5 of the 16 initially healed patients. In a retrospective multicenter study of 119 patients with Crawford type-II congenital pseudarthrosis of the tibia followed to maturity, Shah et al. reported an 86% primary union rate, with 69% still united at maturity5. They did not identify specific factors influencing rates of union or refracture and recommended a larger, prospective, multicenter study. Three-Dimensional Printing Three-dimensional printing, originally known as additive manufacturing, creates models by printing layers of materials on top of one another. These models can be physically held, manipulated, and studied, providing the surgeon preoperative assessment of the specific anatomical geometry. Haleem and Javaid6 described methods to create 3-dimensional models for preparation and practice of orthopaedic procedures. Exact fit models, based on magnetic resonance imaging (MRI) or computed tomography (CT) scanning techniques, can allow for preoperative planning and mock surgical procedures and can create implants specific for complex cases. Corona et al.7 described using 3-dimensional printed titanium truss cages in conjunction with the Masquelet technique to treat massive infected posttraumatic defects. Bone Defects Nauth et al.8 described a 3-stage protocol of (1) radical debridement and resection of infected skeletal elements; (2) defect space management using antibiotic blocks, spacers, or beads, which provide a local depository of culture-specific antibiotic and develop a vascularized membrane; and (3) 8 weeks later, carefully opening the membrane and exchanging the spacer for an autologous graft. Napora et al.9 described excellent functional outcome of patients at 2 to 8 years after tibial defects were treated with bone transport using a stacked hexapod frame. Corticotomy and transport were delayed for 6 to 8 weeks in patients undergoing concurrent flap coverage. The authors noted improved ease and accuracy of the docking with hexapod frames and described a method to augment frame stability near the end of treatment. The Short Musculoskeletal Function Assessment (SMFA) score was not influenced by age, sex, or diabetic status. Seventeen of 38 patients required an additional fixation surgical procedure (plate, nail, or fixator reapplication) at some point during their treatment. Barinaga et al.10 published a case report of successful tibial bone transport combining the use of a motorized magnetic lengthening nail and a limited contact dynamic compression plate, sparing the patient adjunctive external fixation. Limb Lengthening Distraction osteogenesis is the spontaneous formation of new bone in a gradually widening osteotomy site using external fixation. The more recent development of motorized internal limb-lengthening nails has advanced the capabilities of treating patients with limb lengthening and reconstruction needs. Additional authors have reported safe and successful lengthening with motorized intramedullary devices. Iobst et al.11 reported on simultaneously performing distal femoral angular correction and insertion of a retrograde intramedullary lengthening nail, while controlling the fragments with a temporary intraoperative external fixator. Length was subsequently achieved with the motorized intramedullary lengthening nail. Acute corrections of up to 15° were possible with the technique. The authors preoperatively planned their cases using the Baumgart method of reverse planning. Magnetic lengthening nails were used with liberal application of blocking screws preventing postoperative deformity. A cost study suggested that patients undergoing intramedullary lengthening have higher initial implant costs than fixator lengthening over a nail, but the former undergo fewer procedures overall12. Reuse of a PRECICE nail (Nuvasive) was reported in a case of a femoral discrepancy after an infection in which a 3-cm lengthening was successfully performed, distal locking screws were removed, the telescopic portion of the nail was retracted, and a second corticotomy and lengthening were performed13. Radiographic evaluation of bone regenerate formation during lengthening is possible by a number of means. A radiographic pilot study by Vulcano et al.14 found that a pixel-density ratio of >0.89 (ratio of pixel density in the regenerate relative to the surrounding cortex) may correlate with osseous healing and may be the threshold for allowing full weight-bearing. In pediatric patients, Archer et al.15 also found that the most reliable radiographic assessments of regenerate were by the pixel value ratio and the Ru Li technique. The mechanical environment of distracted callus affects the quality of new bone formation. An ovine study was performed by Claes et al.16 in which lateral callus distraction was undertaken in tibiae and various cyclic loads were applied at the end of lengthening. Tibiae that underwent compressive loading had more bone formation, higher spicule height, and higher blood vessel density than those experiencing shear or distractive loading. Growth Prediction Makarov et al.17 evaluated 77 patients at their institution, comparing the predictive accuracy of the White-Menelaus, Anderson-Green, Moseley, and multiplier methods for correctly timing epiphysiodesis. Final leg-length prediction errors varied from 0.7 to 1.1 cm, with the multiplier method proving to be the least accurate. Makarov et al.18 also reported a 7% complication rate among 863 epiphysiodeses, the most common of which was incomplete arrest in 31 patients resulting in angular deformity and requiring reoperation in half of such cases. Physeal Violation A sheep model was used by Knapik et al.19 to assess the consequences of distal femoral physeal violation by a retrograde intramedullary implant, noting that violations of ≤7% of the cross-sectional area were associated with continued growth of the physis without bar formation. Congenital Limb Deficiencies A review from the Finnish Register of Congenital Malformations and Care Register for Health Care20 identified all children born with lower-limb deficiencies, comparing their hospital admissions and stays with the general pediatric population of Finland. In the 16-year study period, the authors found that children with lower-limb deficiencies (terminal, long bone, foot, and toe) had 6 times the number of hospital admissions and 10 times the number of days in the hospital per child than all of the children born without limb deficiency. Two-thirds of the patients born with congenital lower-limb deficiencies required an operation, and approximately half of those operations were orthopaedic. The ratio of the short lower extremity to the contralateral, longer lower extremity in patients with congenital deficiencies has historically been considered constant in the orthopaedic literature. Tsai et al.21 attempted to verify this concept of constant inhibition and to further elucidate the pattern of skeletal maturation in patients with fibular hemimelia. They confirmed the concept of constant inhibition, with a mean deviation ranging from 0.1% to 3.3% in the femur and 0.1% to 3% in the tibia. They also noted that the growth patterns of the lower extremities in patients with unilateral fibular hemimelia did not differ when compared with the normal population. Kowalczyk and Kuźnik-Buziewicz22 reported outcomes of rotation-plasty for unilateral proximal femoral focal deficiency, reviewing postoperative function, time to knee fusion, and complications in 8 adolescents followed for 6 to 12 years postoperatively. Intensive preoperative physical therapy was performed to maximize strength and motion, especially ankle dorsiflexion. Patients were all pain-free and were able to walk without assistive devices. The 2 patients who did not exhibit a Trendelenburg gait had undergone preoperative hip stabilization procedures. Spontaneous derotation of the foot occurred in 5 of 8 patients, necessitating a repeat surgical procedure in 2 patients. All patients reported acceptance of the limb appearance and satisfaction with the result. Radhakrishna et al.23 reviewed 6 patients with Jones type-II tibial hemimelia presenting with an absent distal part of the tibia who were treated with limb salvage. All patients were reconstructed with the following elements: gradually moving the fibula distally using an external fixator to normalize the relationship of the proximal parts of the tibia and fibula; centralizing the fibula with creation of a synostosis between the fibula and tibia; and centralizing the foot relative to the fibula distally, creating a fibular-talar fusion, using external fixation and soft-tissue releases. The mean increase in leg length was 4 cm, with a mean time of 43 days in the fixator. Each child required 2 to 4 procedures, with all patients achieving union. Walker et al.24 analyzed a group of patients with ulnar deficiency and noted that a lower-extremity deficiency was present in 55% of patients. The patients with lower-extremity deficiencies and ulnar deficiencies had less severe presentation of ulnar deficiency. The authors observed no patients with tibial hemimelia (pre-axial deficiency) associated with ulnar deficiencies (post-axial deficiency). They pointed out that the upper-limb bud forms earlier than the lower-limb bud, considering the possibility that a developing limb insult would explain the observation that more lower-extremity involvement was related to less upper-extremity involvement. Physeal Arrest and Epiphysiodesis Physeal bar formation was assessed in a rat model by Wattenbarger et al.25. They selectively induced injury by scraping and drilling the metaphyseal and epiphyseal sides of the physis. Basement plate penetration on the epiphyseal side was associated with radiographic and histologic physeal injury, whereas hypertrophic zone violation on the metaphyseal side was associated with continued growth. Arthroscopic and navigation-assisted physeal bar resection is being increasingly reported. Miyamura et al.26 reported a case with a 2-year follow-up of a distal radial bar excision and concomitant osteotomy, planned using 3-dimensional CT, patient-specific guides, and intraoperative endoscopic visualization. Foot and Ankle Ankle arthrodesis for neuropathic foot deformity is historically associated with poor union rates. A fusion technique combining an external fixator and an intramedullary nail was reported to achieve fusion in 22 of 24 patients by El-Mowafi et al.27. Neuropathic foot deformity with concurrent osteomyelitis is the subject of an article by Kliushin et al.28. Seventy-seven patients were treated for a mean time of 180 days in an external fixator, with infection eradicated in 90.9% of patients at a 1-year follow-up. The American Orthopaedic Foot & Ankle Score (AOFAS) increased marginally, which the authors attributed to the pain component of the outcome score. Brandão et al.29 discussed the management of diabetic neuropathy of the foot with both internal and external fixation techniques, with particular attention to the concept of beaming of the midfoot with axial internal fixation. This concept was described as stiff, thick, intramedullary longitudinal support from hindfoot to forefoot. Staged distraction osteogenesis and ankle arthrodesis were performed by Lou et al.30 in 12 patients with posttraumatic or infectious bone loss of the distal part of the tibia who were treated with simultaneous proximal lengthening and distal compression osteosynthesis using circular fixation to provide ankle fusion. The AOFAS improved from a mean of 37.3 to 75.3 points, and successful regenerate was formed in all, although 2 patients underwent bone-grafting. Ahmad et al.31 reported the results of the treatment of rigid equinus foot deformity with circular external fixation in an adolescent and pediatric population. They reported a mean correction angle of 47.4°. Pin-track infections occurred in 4 of the 30 patients. Equinus deformity secondary to burn contractures treated with circular external fixation was the subject of a report by Zhang et al.32. The authors described a wire technique in the foot, predominantly using hindfoot wires, recognizing the need to avoid injury to the posterior tibial neurovascular bundle. A cadaver study by Kelly et al.33 identified safe hindfoot wire insertion using an entry point one-third of the distance along a line from the posterior aspect of the calcaneus to the lateral malleolus to predictably avoid the posteromedial neurovascular bundle. Nepalese children who were 1 to 5 years of age and had neglected clubfoot deformity were treated by the Ponseti method34. Ninety-five percent of feet remained plantigrade at a minimum of 10 years. Despite some residual deformity, patient-reported outcomes were satisfactory, with a relapse rate of 3%. Trauma The role of external fixation in the management of tibial fractures was described in a number of publications. In a retrospective study, Berven et al.35 compared Ilizarov frame fixation with locking plate fixation of proximal tibial fractures between 62 patients treated at 1 center using the Ilizarov technique and 68 patients treated at a different institution using internal fixation. Time to union was considered faster in the internal fixation group. Deep infection, alignment, reoperation, and range of motion were similar in the 2 groups. Lovisetti et al.36 reported the results of circular external fixation in bicondylar tibial plateau fractures, with a mean follow-up period of 37.3 months. All 20 cases were initially managed with knee-spanning fixation. The results were measured by radiographs and Hospital for Special Surgery (HSS) score and were described as favorable when compared with other series presented in the literature. Napora et al.9 examined functional outcomes in 38 patients with infected tibial nonunion managed with stacked hexapod external fixators for the purpose of bone transport. Corticotomy and transport were delayed for 6 to 8 weeks in patients undergoing concurrent flap coverage. The study noted that, with an intact fibula, the proximal and distal portions of the frame programs must be a mirror image of each other and that if angular, translational, rotation, or additional length deformity correction is built into the frame, a fibular osteotomy is required. Patients completed an SMFA survey at the time of final follow-up. The SMFA score was not influenced by age, sex, or diabetic status. Of 38 patients, 17 required an additional fixation surgical procedure (plate, nail, or fixator reapplication) at some point during their treatment. Arsoy et al.37 reported that patients presumed to have aseptic nonunion but later determined to have positive cultures had an 84% union rate with systemic antibiotic therapy. Tumor Elalfy et al.38 determined that chemotherapy had a negative effect on bone healing and diminished bone hypertrophy when using modulated compliant compressive forces to induce osteointegration in a tumor prosthesis. The 49 patients receiving chemotherapy postoperatively had less bone formation than the 44 patients who did not receive chemotherapy. Implant survival was not affected by chemotherapy, with 10-year survival rates of 85%. Limb-salvage techniques in the management of pediatric sarcoma continue to evolve. Segmental metadiaphyseal distal femoral defects after resection can be reconstructed with a novel vascularized fibular A-frame technique, augmented with an intramedullary nail. This provides a biological reconstruction with greater cross-sectional area than a single vascularized fibula, with a segment amenable to later limb lengthening39. For patients with limb growth potential remaining who require endoprosthetic reconstruction, growing prostheses are described. These include both minimally invasive devices (requiring lengthening under fluoroscopic guidance) and noninvasive devices (driven by an external magnet), and these were compared in a survival analysis by Medellin et al.40. Prosthesis survival was demonstrated as 79% (minimally invasive) and 70% (noninvasive) at 10 years. Patients receiving noninvasive prostheses had a higher mean Musculoskeletal Tumor Society Score (27 points) compared with patients who received minimally invasive devices (24.7 points), which, although not attaining significance (p = 0.295), was attributed by the authors to higher patient satisfaction, better gait, and greater independence. A novel approach to limb salvage in sarcoma of the distal part of the tibia was also described by Lou et al.30, with 5 patients undergoing resection of tumor (including the distal part of the tibia and the talar chondral surface) and subsequent tibial bone transport to achieve tibiotalar fusion. The segment was plated 1 month following the transport phase to expedite frame removal, with mean final Musculoskeletal Tumor Society Score of 88 points.

Objective To compare circular and monolateral external fixators used for bone transport in the treatment of lower limb bone defects. Methods From January 2011 to April 2013, 42 patients with lower limb bone defects were treated in our department. Monolateral external fixator was used for bone transport in 20 patients. They were 14 males and 6 females, with a mean age of 31.6 years (from 20 to 53 years). Ten cases had femoral defects and 10 tibial defects. Circular external fixator was used for bone transport in the other 22 patients. They were 13 males and 9 females, with a mean age of 33.6 years (from 16 to 56 years). Five cases had femoral defects and 17 tibial defects. Time for fracture union, complications, and Paley s criteria for bony and functional recovery were documented. Results All the patients were followed up for 6 to 38 months (mean, 20.3 months). Bony union as achieved between all the bone segments. There were no significant differences between the 2 groups in the bone union index (1.8±0.4 m/cm versus 1.6±0.3m/cm) (P > 0.05). By the Paley's criteria for bony recovery, 17 cases were excellent and 3 fine in the monolateral fixator group while 20 were excellent and 2 fine in the circular fixator group. By Paley's criteria for functional recovery, 17 cases were excellent and 3 fine in the monolateral fixator group while 16 were excellent and 6 fine in the circular fixator group. By the Paley's criteria, there were no significant differences between the 2 groups with regard to secondary, primary and real complications (P > 0.05). Conclusions Both circular and monolateral external fixators are effective in bone transport to treat lower limb bone defects. The monolateral fixator is more tolerable for patients with femoral defects. The circular fixator is more advantageous for patients with complex long shaft defects because it allows for deformity corrections during bone transport. Key words: External fixators; Bone lengthening; Postoperative complications; Ilizarov technique

Clinical Faceoff: The Complex Tibial Plafond Fracture: ORIF or Circular External Fixation?

Treatment of tibial nonunion with bone loss is extremely difficult. A variety of techniques have been described, but each has shortcomings, in particular prolonged external fixation time as well as serious complications such as nonunion and infection. Accordingly, we developed a technique that seeks to reduce these complications by using a circular external fixator in addition to an intramedullary nail to achieve union, limb lengthening, and stability of the regenerated segment. First, the pseudoarthrosis area is resected, and acute compression is continued until bone contact at the docking site was achieved. Then primary grafting is applied to the docking site using a graft harvested from the patient's iliac bone, and the predrilled nail holes localized on the middle segment of the tibia are locked with a free-hand technique. Finally, lengthening is performed to overcome the leg-length discrepancy with an external fixator. Between 2008 and 2011, this technique was used to treat five patients with tibial nonunion with bone loss. All patients were available for a minimum of a 14-month followup (mean, 30months; range, 14-58months). General indications for the procedure were age older than 16years, tibial nonunion with bone loss, and the absence of any psychiatric disorder. We evaluated external fixation time, external fixation index (defined as the duration of external fixation in months divided by the total amount of bone transported and/or the amount of lengthening in centimeters), and time to union on plain radiographs, clinical results using the Paley bone and functional assessment scores, and postoperative complications from chart review. The external fixation time was 4months (range, 3-5months), and the average external fixation index was 0.4months/cm. The mean time to bone union was 4.6months (range, 3.5-5.5months). All angles were determined to be in the normal range. No patients developed refracture or malalignment either on the docking site or the osteotomy site. Paley bone evaluation results were excellent in all five patients, and Paley functional results were excellent in four and good in one. We observed 10 pin-site infections as minor complications, and one patient was left with a residual equinus deformity of 5° as a major complication according to the Paley classification. Our technique combining acute shortening and distraction osteogenesis had promising results for the treatment of tibial nonunion with bone loss in a small group of patients. However, future studies directly comparing available approaches to this difficult problem are required. Because this problem is uncommon, these studies will almost certainly require the cooperation of multiple large participating centers. Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

The reconstruction of long bone defects after tumor resection has been a challenge to the reconstructive surgeon. Increased survival of patients with aggressive or malignant tumors of the extremities has made microsurgical reconstruction more relevant in improving their quality of life. In order to avoid amputation, these long defects are often reconstructed with vascularized autogenous fibular grafts. Vascularized fibular grafts have been reported to have a high union rate and good functional outcome. Union rates for vascularized fibular grafts range from 68-100% in individual case series. However, complications are also frequent. The reported complication rates range from 10-60%, with infection and non-union as the most frequent complications. Revision surgery in the form of additional bone grafting is often needed as well as revision of fixation of the graft. The devices used for fibular autograft fixation include plate and screws, intramedullary nails, circular external fixator, and a combination of K-wires and screws with casting. Rigid fixation is necessary to achieve early adjacent joint motion and prevent graft non-union. Aside from bone union, functional assessment is important in the evaluation of patients treated with microsurgical reconstruction using the fibular graft. The most frequently used functional tool was the modified Enneking MSTS score (Musculoskeletal Tumor Society Score). A retrospective review of patients diagnosed with benign aggressive or malignant extremity tumors with post-oncologic long bone extremity defects reconstructed with vascularized fibula grafts was undertaken from 1993 to 2008 to determine clinical outcome, bone union and functional outcome. A total of 25 patients were able to fulfill the inclusion criteria and were included in the review. Of the 25 patients, eight had benign-aggressive tumors while 17 had malignant tumors. Results showed a union rate of 84% (21/25). Revision surgery was done on seven patients (28%) to achieve union, all of them in the upper extremity. Three patients had infections (12%), and only 2 grafts had fractured (8%). The average length of the fibular graft was 18.22 ± 3.5 cm. Final union time for the grafts to unite was 10.4 ± 4.1 months. The average functional score using the Musculoskeletal Tumor Score in 20 patients was 83.4% (SD, 10.4). The average follow-up was 41 (SD, 32) months. On the latest follow-up, of the 14 patients with malignant bone lesions, two died of the disease and one died of other causes, the rest of the patients with malignant lesions are alive with no evidence of disease. In summary, the use of vascularized fibula autografts for long bone defects after tumor resection represents a valid option of reconstruction. Union rates are high and complication rates are manageable. Among the factors investigated, only graft union was significantly associated with the MSTS score. Patients whose graft united tend to have an MSTS score of 13.8 percentage points higher than those patients who had non-unions.

Lower limb length discrepancy (LLD) in children and adolescents, often due to congenital or acquired conditions, is treated to achieve limb equality and alignment, optimizing function and minimizing cosmetic concerns for an active adulthood. This study evaluated the Health-Related Quality of Life (HRQoL) and physical functioning of adults who underwent unilateral limb lengthening with circular external fixators (EFs) in childhood. Fifty patients treated at a median age of 14.9 years completed the Short Form 36 (SF-36) and Stanmore Limb Reconstruction Score (SLRS) questionnaires in adulthood, with a median follow-up of 8.9 years. Among the 50 patients, 38 underwent a single limb lengthening (21 tibia, 12 femur, 5 both), while 12 required multiple cycles. The median residual LLD was 0.4 cm, with 12 patients (24%) having over 2 cm. Complications occurred in 67% of procedures, mainly due to prolonged healing. Physical and mental health scores were significantly lower than normative data. The mean Physical Component Summary was 52.2 ± 7.2 (p = 0.20). The mean Mental Component Summary was 43.9 ± 8.6 (p = 0.001), notably lower in congenital LLD cases. Many SLRS items (Pain, Social, Physical Function, Work, and Emotions) strongly correlated with SF-36 items. Adults treated with distraction osteogenesis for congenital LLD show normal physical but lower mental health scores compared to peers. Lengthening procedure characteristics did not significantly impact mental health. Routine psychological and social assessments are recommended to prevent long-term distress by providing appropriate support.

High-energy open fractures of the tibia have traditionally been fraught with challenges to include bone comminution or loss, soft tissue loss, nonunion, and infection. A number of techniques have been implemented to treat the severe soft tissue loss typically involving the anteromedial surface of the tibia to include wet-to-dry dressings or Papineau techniques, negative pressure wound therapy, acellular dermal matrices, and rotational or free tissue transfer with Masquelet technique, primary shortening, and distraction osteogenesis to address bone loss. We present a novel technique and subsequent case series that obviates the need of free tissue transfer while treating high-energy type IIIB open tibia fractures by performing an acute shortening and angulation of the tibia and rotational muscle flap coverage and split-thickness skin grafting of the soft tissue defect. Distraction histiogenesis with circular external fixation is then used to correct the residual osseous deformity while stretching the rotational muscle flap.

A retrospective comparative study of corrective osteotomy for tibial deformities with the multiaxial correction fixator and the circular fixator

Objectives:Revision ACL-reconstruction can be compromised by bone loss as result of tunnel widening or poorly placed tunnels. Two-stage revision ACL consist of initial removal of the old fixation hardware and remaining ACL-graft tissue, followed by bone grafting of the tunnels. After a period of graft incorporation and bone remodeling, an ACL-reconstruction is performed. Our primary aim is to examine the use of supercritical carbon dioxide sterilized bone allograft for tunnel grafting in order to determine the bone quality, graft incorporation and remodeling, by using histology and histomorphometric analysis. Secondarily, we aimed to determine whether the histological findings correlate with the timing of the second stage revision procedure.Methods:Case Series. 12 subjects underwent 2-stage revision ACL reconstruction. Femoral and tibial tunnels were bone grafted with supercritical carbon dioxide sterilized bone allograft (Australian Biotechnologies). Mean time from bone grafting to 2nd stage was 8.8 months (range, 5.6 to 21.3 months). Bone biopsies were taken at the time of the 2nd surgery and decalcified and embedded in paraffin. Sections were hematoxylin and eosin stained for microscopic analysis.Results:The graft material was easily identified by its necrotic appearance with empty osteocytes lacunes within the lamellar trabecular bone. In all tissue samples predominately lamellar host bone apposition was seen on the surface of graft fragments known as creeping substitution. Separate bone graft fragments were bridged by newly formed woven bone. In the histological sections of 2 subjects some small islands of chondral cell differentiation were seen, which may relate to endochondral ossification. Active bone remodeling and resorption through combined osteoclastic and osteoblastic activity was present in 2 subjects (7.0 and 6.3 months post grafting), suggesting more advanced phases of graft incorporation. Mean bone volume was 68% over tissue volume (range 33-92%), and graft volume over bone volume was 41% (range 19-70%). Subgroup analysis for graft volume to time of second stage could not demonstrate a difference in 6 to 9 months (mean 44%, range 19-70 %) and >10 months (mean 34%, range 19-48%).Conclusion:The osteoconductive supercritical sterilized bone allograft acted as an effective structural framework, allowing for successful graft incorporation through creeping substitution. Although cancellous grafts may remodel completely with time, the initial bone apposition on and bridging of graft fragments provides early mechanical strengths to facilitate 2-stage revision ACL reconstruction. Bone volume and graft volume varied among subjects, but no beneficial effect was demonstrated for graft incorporation and bone remodeling in delaying the 2nd stage procedure for more than 6 months.

To report on a novel surgical procedure to treat a long segmental tibial defect in a five-year-old 5 kg spayed female Main Coon cat using transverse distraction osteogenesis in the contralateral tibia to create a free autograft. A long free bone segment was created from the cranial half of the normal tibia. A circular external fixator was constructed to give the segment 7 mm of cranial distraction. After 42 days the widened section of tibial bone was removed and transferred to the defect in the contralateral tibia. Locking plates were used to stabilize the graft and to protect the donor tibial sites. By 27 months, both tibias were healed, all implants had been removed, function was excellent, and the overall limb length was 90% of the normal side. Compared with longitudinal distraction osteogenesis in long bone defects, transverse distraction of a normal bone requires a significantly shorter distraction distance to produce a similar amount of bone. Thus, distraction time is reduced, with less likelihood of significant soft tissue damage. New bone may be more reliably regenerated in a normal limb due to better tissue health, and native bone may be more readily incorporated than allografts in compromised sites. Disadvantages include the increased morbidity, as well as the risk and expense associated with involvement of a normal limb.

Free fibular graft still has a place in the treatment of bone defects

Objective: To evaluate the postoperative clinical outcomes of patients undergoing fibular grafting due to bone loss caused by metatarsal tumors. Methods: This retrospective cross-sectional study was conducted between January 2010 and December 2018 with three patients who were treated with a free fibular graft after bone loss due to metatarsal tumor resection. The patients underwent surgery with a dorsal longitudinal incision over the tumor lesion for subsequent tumor resection. The fibular graft was harvested from the distal third of the ipsilateral leg. The graft was fixed using Kirschner wires and a mini-fragment plate and cortical screws. An analysis of the patients’ ages, sex, tumor types, need for adjuvant or neoadjuvant therapy and postoperative complications was conducted. Results: All three patients who were subjected to fibular grafting for metatarsal replacement were female (100%), with a mean age of 10.3 years (± 0.61). The type of tumor found in the three patients (100%) was an aneurysmal cyst, and only the affected metatarsal showed changes. None of the patients required adjuvant or neoadjuvant therapy. Regarding the postoperative complications, two patients (66.6%) presented pseudoarthrosis, and one did not present any complications. Conclusion: Free fibular grafting is a viable option for the treatment of bone loss caused by metatarsal tumors. Level of Evidence IV, Therapeutic Studies; Case Series.

Objective To probe into the role of bone transport on managing tibial bone defect accompanied by anterior-medial soft tissue loss. Methods Orthofix external fixator of lower limb reconstruction system were applied to the medial or anterior-medial side of 57 injured legs. The average tibial defect is 11 (5-20) cm, the largest skin loss area on the anterior-medial side of the leg is 20 cm×8 cm, the smallest area is 5 cm×4 cm. Twelve cases underwent subperiosteal osteotomy in the primary stage; remaining 45 cases underwent secondary osteotomy 2-6 weeks after debridement. The bone segments were transported 10-14 days following osteotomy and proceeded at a rate of 0.25 mm every 6 hour. In case of soft tissue obstruction, docking site mismatch or limited contact, infection and non-union at the docking site, bone grafting, manipulation and realignment and resection were required. Results The average time of treatment which is from debfidement to removal of external fixator is 21 (11-32) months. A good tibial hone reconstruction was atmined in 56 cases, poor bone formation was observed in one case that healed with bone grafting. Limb length discrepancy is less than 4 ram. All wounds were repaired without flaps. Two patients needed plastic surgery. 26% of cases had their docking site healed spontaneously, 1 patient who had a fistula at the docking site had no infection for over 6 months after debridement. Four patients complained pain around knee joint, 11 complained pain at the legs. Six patients had equinus-varus. Five patients had mild knee flexion deformity, and 4 of them recovered. Conclusion Bone transport is effective and satisfactory for managing tibial bone defect accompanied by anterior-medial soft tissue loss. Key words: Tibia; Wounds and injuries; External fixators

Tibiotalocalcaneal arthrodesis using a posteriorly angled nail for definitive fixation augmented with fibular onlay graft and autogenous tibial bone graft within the surgical technique of retrograde-delivered locked compression nail: A case series