Complete Osteotomy Research Articles

Anatomical Structures at Risk in Percutaneous Distal Bunionette Correction

Introduction/Purpose: Bunionette deformity affects 23% of the population and has numerous surgical options, including a minimally invasive approach (MIA) to decrease complications. Percutaneous surgery is favored by patients as it decreases pain, inflammation, and noticeable incision sites. Three possible osteotomy sites have been identified: proximal, diaphyseal, and distal. The study investigates the anatomic structures at risk during distal osteotomy of bunionette deformity using a Shannon burr. The distal osteotomy site was on average greater than 8mm from the extensor digitorum longus and adductor digiti minimi while it was 1.64mm from the lateral dorsal cutaneous nerve. The study highlighted the challenges posed by minimally invasive approaches to treating bunionette deformity and the need for cautious consideration when utilizing percutaneous methods. Methods: Eleven fresh frozen below-knee amputated foot and ankle cadavers were used for this study. Cadavers were allowed to thaw for 12 hours at room temperature before performing any tissue handling. All cadavers were visually inspected for evidence of gross pathology. Fluoroscopic radiographs were used to inspect for evidence of preexisting pathology of the fifth metatarsal. All cadavers with gross pathology or radiographic fifth metatarsal pathology were excluded from the study. All procedures were performed by a fellowship trained orthopaedic foot and ankle surgeon. Results: All eleven cadavers met the inclusion criteria for this study. The average age of the patients was 66.6 +/- 20.1 years. There were five female feet and six male feet. There were seven right feet and four left feet. Distance from the percutaneous access site was measured to structures at potential risk. The closest structure at risk was the lateral dorsal cutaneous nerve (LDCN) (1.64 mm), which was contacted 2/11 times and transected both times. The extensor digitorum longus (EDL) and abductor digiti minimi (ADM) had no instances of contact during the procedure. Dissection allowed for the identification of structures at risk and the assessment of osteotomy. All procedures resulted in a complete osteotomy. Conclusion: Overall, distal percutaneous bunionette osteotomy is largely safe. Structures pertinent to the surgery were identified with ease and were intact after osteotomy with a Shannon burr. Anatomic variations of LDCN can present challenges to the procedure. Meticulous dissection and judicious use of fluoroscopy can help prevent further damage. Surgeons should be aware of anatomic variations in order to proceed safely.

Hemi-high tibial osteotomy: technical note and case report

High tibial osteotomy (HTO) is a widely performed procedure, with several surgical techniques described to treat varus mal-alignment and medial compartment arthrosis of the knee. In our case report, we present a new surgical technique for performing a medial open wedge HTO in a young patient with proximal varus deformity of the right knee to avoid the clinical complications of HTO. A longitudinal medial incision was made medially over the proximal tibia, the medial collateral ligament (MCL) split, and an osteotomy was made from the medial cortex exiting into the “lateral tibial spine”. The osteotomy was then opened. A wedge measured 12.5 mm, and a bone graft harvested from the right iliac crest was used to fill the defect, followed by a Puddu plate placement. We had planned to have the osteotomy exit in the centre of the knee. Two years postoperatively, complete osteotomy healing and full range of right knee movement with no pain were observed. Radiographs confirmed deformity correction. Many surgical techniques have been described for HTO, including closing wedge osteotomy, opening wedge osteotomy, dome osteotomy, progressive callus distraction, and chevron osteotomy. We believe that in this technique, the risk of nonunion is less, the construct is more stable, and the patient will have a faster rehabilitation program with early weight-bearing. Hemi-HTO is a new surgical technique that can be used to treat proximal varus deformity of the knee, especially if the lateral tibial plateau appears radiologically normal.

Efficacy and Reliability of Percutaneous Gigli Saw Osteotomy in Midfoot Surgery: A Cadaver Study.

Midfoot osteotomy is often used in the surgical treatment of foot deformities. The percutaneous Gigli saw osteotomy (PGSO) technique has many advantages compared with known osteotomy techniques. We aimed to show the efficacy and reliability of the PGSO technique in the midfoot of fresh frozen cadavers without using an image intensifier. Four mini-incisions were performed on the dorsomedial, dorsolateral, plantar medial, and plantar lateral regions of the midfoot. Subperiosteal tunnels were then opened with a thin bone elevator, and the four incisions were combined with each other. The Gigli saw was tied to suture material and passed through the tunnels. The PGSO was performed in the midfoot of 12 feet of the cadaver specimens without using an image intensifier. Cadaver specimens were dissected, and injured structures were noted. The mean ± SD (range) cadaver age was 81.16 ± 10.38 years (65-93 years) and weight was 60.86 ± 12.39 kg (49.8-81.6 kg). All of the osteotomies were adequate as planned in the cuboid-cuneiform level and all of them were complete osteotomy .Incomplete osteotomy was not observed in any cadaver specimens. In one specimen, a complete injury of the peroneal tendons (peroneus longus and brevis) was detected. In another specimen, an incomplete tibialis anterior tendon injury was detected. There was no iatrogenic neurovascular injury in the specimens. The PGSO technique is recommended for use even by inexperienced surgeons owing to its minimal risk of soft-tissue injury, provision of a complete osteotomy line, and easy application with limited incisions.

Unstable Lateral Hinge Fracture or Occult Complete Osteotomy Adversely Affects Correction Accuracy in Open-Wedge High Tibial Osteotomy

To verify whether lateral hinge fracture (LHF) affects correction accuracy in open-wedge high tibial osteotomy (OWHTO) and to identify the fracture characteristics responsible for inaccurate correction, including LHF type and hinge location. Patients undergoing OWHTO with locking plate fixation between 2010 and 2016 were retrospectively reviewed. Patients who did not have a minimum 2-year of follow-up or postoperative long-standing hip-to-ankle radiographs were excluded. Correction accuracy was assessed using the weight-bearing line ratio: 57% to 67%, planned correction; 50% to 70%, acceptable correction; otherwise, inappropriate correction. The association between LHF and correction accuracy was assessed using the χ2 test. To identify the fracture characteristics responsible for inaccurate correction, LHF type (stable type 1 and unstable types 2 and 3) and hinge location (shallow osteotomy, deep osteotomy, and occult complete osteotomy) were analyzed using ordinal logistic regression analysis, taking other related demographic and radiologic factors into account. Clinical outcomes according to LHF type were evaluated using the Hospital for Special Surgery scores. A total of 148 cases were included; 41 (27.7%) showed LHF: type 1, 32 cases; type 2, 7 cases; and type 3, 2 cases. Planned, acceptable, and inappropriate corrections were noted in 63 (42.6%), 36 (24.3%), and 48 (32.4%) cases, respectively. LHF had a significant association with correction accuracy (P= .010). Regarding fracture characteristics, unstable LHF and occult complete osteotomy were significant risk factors (P= .016 and P= .004, respectively). Specifically in cases of stable LHF, occult complete osteotomy adversely affected correction accuracy (P= .025). No difference was found in the final Hospital for Special Surgery scores according to LHF type (P= .816). LHF affected the accuracy of coronal alignment correction in OWHTO. Unstable LHF or occult complete osteotomy were risk factors for inaccurate correction. Even among stable LHFs, those with occult complete osteotomy could lead to inaccurate correction. Level III, retrospective cohort study.

Endoscopically assisted malarplasty: L-rotation technique

IntroductionEndoscopically assisted malarplasty with a greenstick fracture is a method for preserving the body eminence and improving arch protrusion. However, this technique is inadequate when malar body reduction is required. To compensate for these limitations, we developed a new surgical technique using the endoscope to reduce body protrusion. Material and methodsWe enrolled 261 patients who visited our clinic for zygoma reduction from January 2017 to December 2018. Their mean age was 31 (range 17–63) years. After a scalp incision, an incomplete osteotomy was created from the most prominent portion of the zygoma body to the zygomaticomaxillary suture line. A complete osteotomy was performed on the arch. These osteotomies resulted in an L-shaped zygoma segment after tapping the bone with a mallet. ResultsOf the 261 patients who underwent our L-rotation technique, 242 also received a corticotomy. Of those patients, 15 underwent a different degree of zygoma reduction on both sides. A floating zygomatic segment occurred in four cases, although no further surgery was required. One patient's zygomatic segment dropped on one side, requiring rigid fixation through the intraoral approach. Most patients were satisfied and there were no specific complications. ConclusionsEndoscopically assisted malarplasty using an L-rotation technique enables the protrusion of both the arch and body to be reduced. The zygoma reduction can be modified based on the location of the incomplete osteotomoy line and the number of corticotomies required.

Viability of polyamide 12 intramedullary rods coated with hydroxyapatite in experimentally induced fractures in young roosters (white Plymouth rock)

The present study aimed the viability evaluation of solid intramedullary rods made with polyamide 12 and coated with hydroxyapatite in experimentally osteotomized humerus of young roosters (white Plymouth rock). Sixteen animals of 45 days old each were used. After general anesthesia, they underwent to complete transverse osteotomy of the right humerus diaphysis to implant the already described rods which filled the entire length of the medullary cavity and were fixed by two cortical stainless steel screws in each bone fragment. The surgical technique was well succeeded without any trans-operative intercurrence. Through clinical and radiographic examination, it was observed that soon after the anesthesia recovery, six rods (37,5%) broke next to the fracture focus and the same was noticed with the others (62,5%) on seventh day post-surgery. Based on the obtained results, it can be hypothesized that polyamide 12 rods resistance could have been affected by all the thermal stages necessary to its incorporation with hydroxyapatite. Furthermore, the roosters’ age may also have contributed to adverse outcomes. However, future researches will be necessary to confirm those hypotheses.

The Effects of Autologous Platelet-Rich Plasma on the Bone Fracture Healing in Rabbits

The purpose of this study was to evaluate the effects of an autologous platelet rich-plasma on femoral fracture healing in experimentally induced rabbits’ model. In this study, 34 local breed rabbits, around 2-2.5 kg body weight, were divided into two equal groups randomly; Group A: platelet-rich plasma (PRP) and Groups B: Control group. Rabbits in both groups underwent a complete mid-shaft transverse osteotomy of the femur by a fine electrical saw. After fracture induction, the rabbits in group A (PRP group) were treated by application of 0.5 ml of autologous PRP at the site of the fractured bone, while in group B (control), rabbits were injected with distilled water. Samples from the fractured femur were collected at 10th, 20th, 30th days post operation for radiological evaluation and at 10th, 14th, 20th, and 30th days for histopathological evaluation. In radiological study, it was found that the rate of callus formation in rabbits treated with PRP (Group A) were faster than the control group (Group B) at different periods. Similarly, in histological finding it found that the stages of healing were faster in Group A when compared with Group B. It was concluded that using autologous PRP has beneficial effect to enhance the process of bone healing in the rabbit’s model.

Application of three-dimensional printing technology in osteotomy for chin width and prominent mandibular angle

Objective To explore the applied value of computer-aided design and three-dimensional printing technology in osteotomy for chin width and prominent mandibular angle. Methods Sixteen patients with chin width and prominent mandibular angle were admitted to the Plastic Surgery Ward of the Second Affiliated Hospital of Zhengzhou University. All patients underwent preoperative computer-aided design, three-dimensional reconstruction of head and face, reconstruction of mandibular nerve canal, intelligent osteotomy line design of chin and mandible, simulation of chin and mandibular angle osteotomy, 3-D printing of surgical template to complete osteotomy, and internal fixation of chin osteotomy plate. The mandibular angle (Co-Go-Me), mandibular ramus height (Co-Go), mandibular body length (Go-Me), subfacial width (Go-Go’), chin nodule width (Ge-Ge’) and face height (N-Me) were measured preoperation, before surgical simulation and postoperation. Co-Go-Me, Co-Go/Go-Me, Go-Go’/N-Me and Ge-Ge’/N-Me were compared and analyzed in preoperation, before surgical simulation and postoperation. Results All the patients were satisfied with their facial shape. The mandible was almost symmetrical after operation. No complications such as nerve injury and infection occurred after operation, which fully met the preoperative design requirements. The mandibular angles in the left and right sides of patients before operation were significantly less than those after operation (t=2.890, 2.886, P 0.05). The average mandibular angles after operation were (123.9±3.0)°. Co-Go/Go-Me in the left and right sides of patients before operation was significantly higher than that after operation (t=3.607, 2.860, P 0.05). The ratio of the length of the left and right mandibular body to the height of the ascending ramus was close to 2: 1. Preoperative Go-Go’/N-Me was significantly higher than that post-operation (t=3.102, P 0.05). Preoperative Ge-Ge’/N-Me was significantly higher than that post-operation (t=3.010, P 0.05) . Conclusion The application of computer-aided design and three-dimensional printing technology in osteotomy for large chin and hypertrophic mandibular angle can significantly improve the accuracy of operation, reduce the difficulty of operation, improve the cosmetic effect, and reduce the occurrence of complications such as infection and injury of important nerves and blood vessels. Key words: Chin width; Prominent mandibular angle; Computer-aided design; Surgical template; Three-dimensional printing technology

A metaphyseal fracture rat model for mechanistic studies of osteoporotic bone healing.

Most osteoporotic fractures occur at metaphyseal regions of long bones. The present study proposed a clinically relevant animal model that satisfied: i) induction of osteoporosis, ii) unilateral complete osteotomy at metaphysis, iii) internal fixation. 6 months old female Sprague-Dawley rats (n = 64) were randomly divided into the ovariectomised-metaphyseal osteotomy (OVX, n = 32) and metaphyseal osteotomy (SHAM, n = 32) groups. The metaphyseal-osteotomy model was created with a plate-fixation of the osteotomy and assessed by X-ray, micro-computed tomography, histomorphometry and mechanical testing at weeks 1, 3 and 6. X-ray results showed complete healing of metaphyseal osteotomy at week 6. Histology showed 3 stages of metaphyseal healing. Stage 1 was characterised by fibrous tissue, consisting of disorganised orientation of collagen fibres, and infiltration of immune cells. At stage 2, a transitional zone consisting of maturing fibrous tissue and differentiating mesenchymal cells with early trabecular bone formation and disorganised woven bone were observed. During stage 3, cortical bone ends unified and woven bone underwent transformation to lamellar bone. OVX group healing was significantly delayed when compared to SHAM samples. The study demonstrated that healing of osteoporotic osteotomy at the metaphyseal region was delayed in terms of radiography, histomorphometry and mechanical strength. These quantitative evaluations, along with histological features, may provide key references for future studies. The animal model may provide additional clinical relevance as most osteoporotic fracture in humans occurs at metaphyseal regions.

A novel tibial tuberosity advancement technique with cranial implant fixation (TTA CF): a pilot study in sheep

BackgroundCranial cruciate ligament rupture is the most frequent orthopedic disorder in human and animals. An array of surgical techniques have been described to stabilize the stifle joint in dogs, including intraarticular stabilization, extraarticular stabilization, and tibial osteotomy techniques. Tibial plateau leveling osteotomy and tibial tuberosity advancement with a lot of modifications are the most common. In this study we report the possibility of fixing the novel titanium implant for tibial tuberosity advancement with two screws in a craniocaudal direction. The aim of our study was to improve the clinical benefit of the tibial tuberosity advancement surgical technique where an attempt was made to reduce the number of screws and obtain a strong implant fixation with minimal bone traumatization. This way of attachment allows to distribute the forces evenly on medial and lateral side of osteotomy gap.ResultsTibial tuberosity advancement with cranial implant fixation was performed in four sheep. Complete radiographic and clinical follow up was recorded. All four sheep had a complete osteotomy line healing at a mean of 10 weeks postoperative (range 8–12 weeks). None of the animals had osteotomy gap healing grades of poor. Minor complication included the minimally cracked Maquet hole on the postoperative radiographs, without displacement of the tibial crest which occurred in 2 sheep. Major complication grade 1, major complication grade 2 and catastrophic were not found.ConclusionsThe novel surgical technique for tibial tuberosity advancement with cranial implant fixation is technically comparable to the recent trend in tuberosity advancement techniques, where partial osteotomy of the cranial tibial tuberosity crest is performed. A cranial implant fixation allows to distribute the forces evenly on medial and lateral side of osteotomy gap, which may result in less number of major complications in dogs. A novel titanium implant decreases the tibial traumatisation by reducing the number of screws.

A systematic review of current osteoporotic metaphyseal fracture animal models.

ObjectivesThe treatment of osteoporotic fractures is a major challenge, and the enhancement of healing is critical as a major goal in modern fracture management. Most osteoporotic fractures occur at the metaphyseal bone region but few models exist and the healing is still poorly understood. A systematic review was conducted to identify and analyse the appropriateness of current osteoporotic metaphyseal fracture animal models.Materials and MethodsA literature search was performed on the Pubmed, Embase, and Web of Science databases, and relevant articles were selected. A total of 19 studies were included. Information on the animal, induction of osteoporosis, fracture technique, site and fixation, healing results, and utility of the model were extracted.ResultsFracture techniques included drill hole defects (3 of 19), bone defects (3 of 19), partial osteotomy (1 of 19), and complete osteotomies (12 of 19). Drill hole models and incomplete osteotomy models are easy to perform and allow the study of therapeutic agents but do not represent the usual clinical setting. Additionally, biomaterials can be filled into drill hole defects for analysis. Complete osteotomy models are most commonly used and are best suited for the investigation of therapeutic drugs or noninvasive interventions. The metaphyseal defect models allow the study of biomaterials, which are associated with complex and comminuted osteoporotic fractures.ConclusionFor a clinically relevant model, we propose that an animal model should satisfy the following criteria to study osteoporotic fracture healing: 1) induction of osteoporosis, 2) complete osteotomy or defect at the metaphysis unilaterally, and 3) internal fixation.Cite this article: R. M. Y. Wong, M. H. V. Choy, M. C. M. Li, K-S. Leung, S. K-H. Chow, W-H. Cheung, J. C. Y. Cheng. A systematic review of current osteoporotic metaphyseal fracture animal models. Bone Joint Res 2018;7:6–11. DOI: 10.1302/2046-3758.71.BJR-2016-0334.R2.

The effects of pentoxifylline adminstration on fracture healing in a postmenopausal osteoporotic rat model

Previous studies report positive effects of pentoxifylline (PTX) alone or in combination with other drugs on some pathologic bone diseases as well as an ability to accelerate osteogensis and fracture healing in both animal models and human patients. The aim of this present study was to evaluate the effects of PTX administration on Hounsfield unit and bone strength at catabolic response (bone resorbing) of a fracture in an experimental rat model of ovariectomy induced osteoporosis (OVX-D). Thirty adult female rats were divided into groups as follows: 1 (OVX, control, no treatment); 2 (OVX, sham: daily distilled water); 3 (OVX, daily alendronate: 3 mg/kg); 4 (OVX, twice daily 100 mg/kg PTX) and 5 (OVX, PTX+alenderonate). OVX was induced by bilateral ovariectomy in all rats. A complete standardized osteotomy of the right femur was made after 3.5 months. PTX and alendronate treatments were performed for eight weeks. Then, rats were euthanized and had its right femur subjected to computerized tomography scanning for measuring Hounsfield unit; eventually, the samples were sent for a three point bending test for evaluation of the bone strength. Administration of PTX with 200 mg/kg and alendronate alone and in combination showed no significant alteration in Hounsfield unit and biomechanical properties of repairing callus of the complete osteotomy compared with the control group. Results showed increased bending stiffness and stress high load mean values of repairing complete osteotomy in PTX-treated rats compared to the control OVX-D.

Reduction malarplasty by bidirectional wedge ostectomy or two percutaneous osteotomies according to zygoma protrusion type.

Reduction malarplasty to correct prominent malar complex is popular in Asians. Despite the popularity of reduction malarplasty, most of the surgical methods applied are not selected according to the degree of zygoma protrusion. In this study, we analyzed the effectiveness of two different surgical procedures to clarify their appropriateness for each zygoma type. One of the procedures used was the "bidirectional wedge ostectomy," in which a bidirectional wedge-shaped bone fragment was removed from the zygomatic body via oral incision and oblique complete osteotomy of the zygomatic arch via sideburn incision. Another was the "quick osteotomy," a greenstick osteotomy of the zygomatic body and complete osteotomy of the zygomatic arch via two skin incisions. We classified zygoma protrusion into two categories: only zygomatic arch protrusion (group 1) and zygomatic body and arch protrusion (group 2). The cross-sectional area of the most prominent malar region decreased by 9.4±2.5mm laterally (zygion-to-zygion) and by 2.9±0.8mm obliquely (average of center-to-right and left maxillozygion) after the ostectomy. However, in patients who underwent the osteotomy, while the cross-sectional area decreased by 10.9±2.7mm laterally, it did not decrease obliquely. Thirty patients (73.2%) in group 1 underwent the osteotomy, and the remaining eleven (26.8%) underwent the ostectomy. In group 2, 83% (n=39) underwent the ostectomy. We were able to find the more appropriate procedure for each zygoma protrusion type through outcome analysis. With these results, we suggest that if each procedure is performed according to this classification, more favorable esthetic results of zygoma reduction can be achieved.

The Mini-Zygoma Reduction Surgery

Reduction of mid-face width is a major concern in Asian facial contouring surgery, and some patients want their mild or borderline problems to be improved in a minimally invasive manner. The authors' mini-zygoma reduction surgery technique is indicated for patients who seek both minimal invasiveness and reliability. Patients presenting with a wide mid-face and isolated zygomatic arch protrusion without severe zygomatic body prominence were included into the study. All surgeries are performed under local anesthesia and on an outpatient basis. Through temporal and sideburn incisions, complete osteotomy was performed on the temporal process of the zygomatic body and just in front of the anterior tubercle of the zygomatic arch. After transposition to a proper inward position, the osteotomized segment was rigidly fixed on the zygomatic arch with metal fixtures. All surgeries were successfully performed without excessive blood loss or any unpredicted events. Over the 6 to 18-month follow-up period, most patients were satisfied with the aesthetic results of the surgery, the rapid recovery, and the minimal postoperative swelling. Even with a 1-point fixation, the segment remained stable and did not show displacement of the bony segment. In patients showing a minimal zygomatic arch prominence and seeking minimally invasive surgery, the proposed technique can be a proper surgical option with reliable and predictable results. The surgery can be performed without general anesthesia and on an outpatient basis, thereby resulting in prompt postoperative recovery. Predictability and reliability is assured with rigid fixation with a metal fixture on the zygomatic arch.

Complete Closing Wedge Osteotomy for the Correction of Tibia Vara- a Technique

Complete Closing Wedge Osteotomy for the Correction of Tibia Vara- a Technique

Visible Perforating Lateral Osteotomy: Internal Perforating Technique with Wide Periosteal Dissection

There are two general categories of lateral osteotomy techniques—the external perforating method and the internal continuous method. Regardless of which technique is used, procedural effectiveness is hampered by limited visualization in the surgical field. Considering this point, we devised a new technique that involves using a wide subperiosteal dissection and internal perforation under direct visualization. Using an intranasal approach, whereby the visibility of the intended fracture line was maintained, enabled a greater degree of control, and in turn, results that were more precise, and thus predictable and reproducible. Traditionally, it has been taken as dogma that the periosteum must be preserved, considering the potential for dead space and bony instability; however, under sufficient visualization of the surgical field with an internal perforating method, complete osteotomy with fully preserved intranasal mucosa could be conducted exactly as intended. This intact mucosal lining compensates for the elevated periosteum. Compressive dressing and drainage through a Silastic angio-needle catheter enabled the elimination of dead space. Therefore, precise, reproducible, and predictable osteotomy minimizing the potential for associated complications such as ecchymosis, that is, bruising owing to hemorrhage, could be performed. In this article, we introduce a novel technique for lateral osteotomy with improved visualization.

Is Erbium:Yttrium-Aluminum-Garnet Laser Versus Conventional Rotary Osteotomy Better in the Postoperative Period for Lower Third Molar Surgery? Randomized Split-Mouth Clinical Study

Lasers have been extensively used in dentistry for several applications. We investigated and compared the use of an erbium:yttrium-aluminum-garnet laser and conventional rotary instruments for bone removal in third molar surgery. We implemented a randomized, split-mouth clinical trial. Patients with bilateral and symmetrical third molar impaction referred to the Department of Oral and Maxillo-Facial Sciences, "Sapienza" University of Rome, were enrolled in the study. Each patient was treated once with the erbium:yttrium-aluminum-garnet laser and once with conventional rotary instruments for bone removal during third molar surgery. Pain, swelling, and trismus were taken into account to match the 2 techniques.In addition, the times required to complete osteotomy and for the full operation were recorded. Descriptive and bivariate statistics were computed, and the P value was set at .05. The sample was composed of 15 patients (8 men and 7 women) ranging in age from 18 to 30 years. Pain perceived in the laser-treated group was significantly less than that in the conventional group(P = .0013). This also was true for trismus (P = .0002) and swelling. The operating time for osteotomy was longer in the laser group. The results of this study suggest that the laser could be an interesting alternative to conventional rotary instruments. Future studies with a larger number of patients are required to confirm the conclusions achieved from this work.

Delayed bone healing following high tibial osteotomy related to increased implant stiffness in locked plating

IntroductionAsymmetrical callus formation and incomplete bone formation underneath stiff locking plates have been reported recently in clinical and experimental fracture healing studies. After similar effects were observed in the outcome of high tibial osteotomy (HTO) patients, a retrospective study was performed to quantify the frequency and level of such incomplete healing cases. Material and methodsTwenty-three patients treated with medial open wedge HTO and locking plate (Tomofix™) for posttraumatic or congenital genu varum were investigated. No bone grafts were applied to fill the osteotomy gap. The median correction angle was 8° (5–18°). Elective hardware removal was performed after a median of 19.5 months (12–58 months) following an uneventful clinical course. The most recent postoperative X-ray available (median 21 months; 13–56 months) was evaluated for consolidation of the osteotomy. We performed an in vitro biomechanical experiment using the same HTO on a loaded cadaver knee joint to compare interfragmentary movements (IFMs) when using regular locking screws with the Tomofix™ plate and screws that enabled dynamic stabilisation of this plate. ResultsFifteen patients (65%) displayed incomplete consolidation of the osteotomy underneath the locking plate (10.9% of the osteotomy length) and cortical deficiency. The time to implant removal for these patients of 27 months was longer than the 21 months for the patients with a complete osteotomy gap healing. The biomechanical experiment demonstrated that very low IFMs and corresponding interfragmentary strain occur underneath the plate when using regular locking screws. Replacement with dynamic screws resulted in an increased IFM. Discussion and conclusionsThese results support the hypothesis that low bone formation underneath locking plates is induced by increased stiffness. This high stiffness situation could be altered by replacing the standard screws with dynamic screws which allow for a movement of 0.35mm perpendicular to the screw axis. This resulted in an approximately threefold increase in the IFM and may be a potential concept to avoid incomplete bone healing under stiff plate fixations.

Surgical Correction of Angular and Torsional Metatarsal Deformity With Cylindrical Osteotomy and Locking Compression Plates in a Calf

To report successful surgical correction of concurrent angular and torsional metatarsal deformities in a calf using a cylindrical osteotomy and locking compression plate (LCP) technology. Case report. A 10-week-old composite bull calf. Using Paley's principles of angular limb deformity correction, a cylindrical osteotomy was performed to concurrently correct varus deformity and external torsion of the metatarsus. The limb was aligned and stabilized using two 3.5 mm broad LCP with locking head screws. The calf was immediately weight bearing after surgery and did not experience any postoperative complications. Follow-up radiographs 5 months postoperatively revealed complete osteotomy healing and remodeling. The limb was in good alignment, the calf was fully weight bearing, and client satisfaction was very high. Telephone follow-up with the owner 16 months after surgery revealed continued full use of the operated limb and the bull was being used in a pasture breeding program. Cylindrical osteotomy with LCP stabilization can provide a favorable outcome in angular and torsional metatarsal deformity correction in cattle.

Piezoelectric Osteotomy for Distraction Osteogenesis of the Pediatric Mandible

Distraction osteogenesis of the mandible requires a complete osteotomy so that the proximal and distal segments may be separated, thereby producing length. One of the main complications of this technique is lingual nerve injury due to trauma induced by either the saw or the osteotome. The purpose of this article was to suggest the use of piezosurgery in performing near-complete osteotomy of either the body or ramus of the mandible. Surgical procedure was performed under general anesthesia, and it lasted approximately 90 minutes. After the buccal cortex of the mandible was dissected, a piezosurgical device was used for the planned osteotomy. The gap created by the device allowed visualization of the nerve, thereby permitting completion osteotomy of the lingual cortex. The patient did not show any neurological postoperative complication. The use of piezoelectric surgery appears to be a safer option in performing distraction osteogenesis of the pediatric mandible. The presumed disadvantage of this technique, notably an increased operating time due to the lower power cut of the piezoelectric device, was not encountered.