Medial Tibial Cortex Research Articles

How does the inclination of the tibial component matter? A three-dimensional finite element analysis of medial mobile-bearing unicompartmental arthroplasty

BackgroundMedial unicompartmental knee arthroplasty (UKA) using Oxford mobile-bearing prosthesis is performed in the treatment of medial compartmental arthritis of the knee. However, little is known about the stress distributions for mobile-bearing UKA on the medial tibial plateau. MethodsIn this study, the stresses on the coronal plane were calculated in a three-dimensional model of the proximal tibia. The features of the stress distribution were investigated when the tibial tray was placed in 15°, 10°, six degrees, and three degrees varus, neutral (0°), and in three degrees, six degrees, 10°, and 15° valgus on the coronal plane of the medial plateau. ResultsThe peak von Mises stress was found on the cortex below the medial plateau while the stresses of cortical bone increased gradually as the inclination of the tibial tray was changed from varus to valgus. The amount of peak stress was almost the same as that in the normal knee model when the tibial tray was placed in six degrees valgus and consistently lower in varus inclination than in the normal knee model. Conversely, the peak stress of soft bone was found at the bottom of the slot. ConclusionsThis study demonstrates that the inclination of the tibial component affects stress distribution in the proximal tibia after UKA. Slight varus inclination of the mobile-bearing tibial component is acceptable as it lowers the peak stress on the medial cortex. Additionally, placing the tibial tray in slight varus avoids a rise in stress between the tip of the keel and the medial tibial cortex.

Technical tip: Removal of a broken tri-cortical syndesmotic screw using a “perfect circle” technique

While broken or loose syndesmotic screws are typically of no clinical consequence, occasionally breakage can result in pain, metal fretting, or bony erosion. Despite quad-cortical syndesmotic screws being relatively easy to remove due to the prominent screw tip penetrating the medial tibial cortex, removal of a broken tri-cortical screw can be technically challenging. The purpose of this manuscript is to describe a safe technique for removing the buried, broken tri-cortical screw fragment via a minimally invasive medial tibial approach by verifying the screw location using intra-operative fluoroscopy.

The effects of kinematically aligned total knee arthroplasty on stress at the medial tibia: A case study for varus knee.

ObjectivesLittle biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments.Materials and MethodsBone models were constructed from one volunteer (normal) and three patients with three different knee deformities (slight, moderate and severe varus). A dynamic musculoskeletal modelling system was used to analyse the kinematics and the tibiofemoral contact force. The contact stress on the tibial insert, and the stress to the resection surface and medial tibial cortex were examined by using finite element analysis.ResultsIn all bone models, posterior translation on the lateral side and external rotation in the KA TKA models were greater than in the MA TKA models. The tibiofemoral force at the medial side was increased in the moderate and severe varus models with KA TKA. In the severe varus model with KA TKA, the contact stress on the tibial insert and the stress to the resection surface and to the medial tibial cortex were increased by 41.5%, 32.2% and 53.7%, respectively, compared with MA TKA, and the bone strain at the medial side was highest among all models.ConclusionNear normal kinematics was observed in KA TKA. However, KA TKA increased the contact force, stress and bone strain at the medial side for moderate and severe varus knee models. The application of KA TKA for severe varus knees may be inadequate.Cite this article: S. Nakamura, Y. Tian, Y. Tanaka, S. Kuriyama, H. Ito, M. Furu, S. Matsuda. The effects of kinematically aligned total knee arthroplasty on stress at the medial tibia: A case study for varus knee. Bone Joint Res 2017;6:43–51. DOI: 10.1302/2046-3758.61.BJR-2016-0090.R1.

Assessing torsion of the medial cortex of the canine tibia using computed tomography multiplanar reconstruction.

To describe a protocol for the measurement of tibial rotational alignment using CT multiplanar reconstructions. To establish the feasibility of producing general guidelines for the amount of torsional contouring to apply to a bone plate applied to the medial aspect of the tibia during repair of a non-reducible tibial fracture. CT scans of the pelvic limbs of 15 chondrodystrophic and 34 non-chondrodystrophic dogs were studied. Medial tibial cortex torsion angle and distal medial tibial cortex angle were determined from CT multiplanar reconstructions. Medial plate application was simulated using a plate contoured to the group mean medial tibial cortex torsion angle and post-simulation tibial rotational alignment was assessed. Mean medial tibial cortex torsion angles were 23° (chondrodystrophic) and 26° (non-chondrodystrophic). Following simulated plate application the change in medial tibial cortex torsion was less than 10° in 73% of chondrodystrophic and 93% of non-chondrodystrophic tibias. In total, 93% of chondrodystrophic and 97% of non-chondrodystrophic tibias had post-simulation distal medial tibial cortex angle less than 10° from the group mean pre-simulation distal medial tibial cortex angle. Medial tibial cortex torsion and tibial rotational alignment can be measured using the protocol described in this study. 26° of internal torsional tibial plate pre-contouring may be appropriate for non-chondrodystrophic dogs, but further clinical validation is required.

Radiographic study on the tibial insertion of the posterior cruciate ligament

ObjectiveTo establish the radiographic distances from posterior cruciate ligament (PCL) tibial insertions centers to the lateral and medial tibial cortex in the anteroposterior view, and from these centers to the PCL facet most proximal point on the lateral view, in order to guide anatomical tunnels drilling in PCL reconstruction and for tunnel positioning postoperative analysis. Study designControlled laboratory study. MethodsTwenty cadaver knees were evaluated. The PCL's bundles tibial insertions were identified and marked out using metal tags, and the knees were radiographed. On these radiographs, the bundles insertion sites center location relative to the tibial mediolateral measure, and the distances from the most proximal PCL facet point to the bundle's insertion were determined. All measures were calculated using the ImageJ software. ResultsOn the anteroposterior radiographs, the mean distance from the anterolateral (AL) bundle insertion center to the medial tibial edge was 40.68±4.10mm; the mean distance from the posteromedial (PM) bundle insertion center to the medial tibial edge was 38.74±4.40mm. On the lateral radiographs, the mean distances from the PCL facet most proximal point to AL and PM bundles insertion centers were 5.49±1.29mm and 10.53±2.17mm respectively. ConclusionsIt was possible to establish a radiographic pattern for PCL tibial bundles insertions, which may be useful for intraoperative tunnels locations control and for postoperative tunnels positions analysis.

Estudo radiográfico da inserção tibial do ligamento cruzado posterior

ObjectiveTo establish the radiographic distances from posterior cruciate ligament (PCL) tibial insertions centers to the lateral and medial tibial cortex in the anteroposterior view, and from these centers to the PCL facet most proximal point on the lateral view, in order to guide anatomical tunnels drilling in PCL reconstruction and for tunnel positioning postoperative analysis. Study designControlled laboratory study. MethodsTwenty cadaver knees were evaluated. The PCL's bundles tibial insertions were identified and marked out using metal tags, and the knees were radiographed. On these radiographs, the bundles insertion sites center location relative to the tibial mediolateral measure, and the distances from the most proximal PCL facet point to the bundle's insertion were determined. All measures were calculated using the ImageJ software. ResultsOn the anteroposterior radiographs, the mean distance from the anterolateral (AL) bundle insertion center to the medial tibial edge was 40.68 ± 4.10 mm; the mean distance from the posteromedial (PM) bundle insertion center to the medial tibial edge was 38.74 ± 4.40mm. On the lateral radiographs, the mean distances from the PCL facet most proximal point to AL and PM bundles insertion centers was 5.49 ± 1.29 mm and 10.53 ± 2.17 mm respectively. ConclusionsIt was possible to establish a radiographic pattern for PCL tibial bundles insertions, which may be useful for intraoperative tunnels locations control and for postoperative tunnels positions analysis.

Comparison Between Two Methods for Arthroscopic Reattachment of Avulsion of the Tibial Spine in Children and Adolescents

This study compares the outcomes from two different methods of tibial spine reattachment - a suture loop pull through versus an endobutton assisted pull through. Arthroscopic treatment tibial spine (ACL) avulsion injuries for Meyers and McKeever grade 2 and 3 in children offers better outcomes than open surgery for pain relief, post-op stiffness and the speed of recovery. Current methods use suture shutting techniques to place a loop around the ACL insertion and pull it through the proximal tibia. This method has a steep learning curve and can be time and difficult in a paediatric knee. We have used a simpler method which involves an intra-articular endobutton to anchor a pull-through suture in the ACL atachment. In both groups the sutures were tied around an endobutton post over the medial tibial cortex. In a retrospective study we compared two case-matched groups of 10 cases each to compare the outcomes of these two methods. Knees in both groups were immobilised in an extension knee brace for 3 weeks and were mobilised thereafter. The surgery was faster in the endobutton group by an average of 12 minutes (p<0.05). The endobutton method allowed more anatomic apposition of the tibial spine. Full range of movement was attained marginally faster in the endobutton group (p>0.07). The results at 12 months were similar. There were not growth plate issues in either group. Both groups required an additional procedure to cut the suture knot and detether the growth plate. A repeat arthroscopy was needed in the intra-articular endobutton group to remove the intra-articular endobutton. In 4/10 cases the intraarticular endobutton was covered in healing scar tissue and was not visualised arthroscopically and was left in-situ. The in-situ buttons have not caused any symptoms to date.

'Trampoline fracture' of the proximal tibia in children: report of 3 cases and review of literature

We present three cases of fracture of the proximal tibia in young children who were jumping on a trampoline. The typical radiological findings and the underlying mechanism of trauma are discussed. The key radiological features are: a transverse hairline fracture of the upper tibia often accompanied by a buckle fracture of the lateral or medial tibial cortex, buckling of the anterior upper tibial cortex and anterior tilting of the epiphyseal plate. New types of injuries related to specific recreational activities are recognized. It is often helpful to associate a typical injury with a particular activity. Trampoline related injuries have increased dramatically over the last years. The most common lesions are fractures and ligamentous injuries, in particular a transverse fracture of the proximal tibia. However the radiological findings can be very subtle and easily overlooked. It is therefore important to be aware of the typical history and radiological findings.

Use of the reamer–irrigator–aspirator technique to obtain autograft for ankle and hindfoot arthrodesis

The use of autograft bone is the best option when undertaking a procedure that requires bone graft because it is osteogenic, osteoconductive and osseo-inductive. Pain, morbidity and complications associated with harvesting iliac or non-iliac sites occur in between 6% and 30% of cases. An alternative source of graft with possibly a lower morbidity is the intramedullary canal. In this study, 28 patients undergoing 30 arthrodesis procedures on the hindfoot had a mean of 48 cm(3) (43 to 50) of bone harvested locally from the hindfoot or the tibial shaft by antegrade or retrograde reaming. No patient sustained a fracture of the calcaneum, talus or tibia. There was no morbidity except for one complication when the reamer breached the medial tibial cortex. This healed uneventfully. This method of using the reamer-irrigator-aspirator system is an extension of the standard technique of intramedullary reaming of the lower limb: it produces good-quality bone graft with viable growth factors consistent with that of the iliac crest, and donor site morbidity is low. This is an efficient method of obtaining autologous bone for use in arthrodesis of the ankle or hindfoot.

Placement of Tibial Intraosseous Infusion Devices

Post-mortem preautopsy multidetector computed tomography was used to assess the placement of tibial intraosseous infusion needles in 52 cases of battlefield trauma deaths for which medical intervention included the use of the technique. In 58 (95%) of 61 needles, the tip was positioned in medullary bone. All 3 (5%) unsuccessful placements were in the left leg, and the needle was not directed perpendicular to the medial tibial cortex as recommended. Considering the nature of military trauma and the environmental conditions under which care is rendered, military medical personnel appear to be highly successful in the placement of tibial intraosseous infusion needles.

Temporary Hemiepiphysiodesis with Blount Staples and Eight-Plates in Pigs

Temporary hemiepiphysiodesis is a relatively minor surgical procedure in the growing child to allow guided growth to correct angular deformities. Blount staples (Stryker Howmedica, Kiel, Germany) have been used effectively for the past 50 years for physeal stapling; their limitations are poor mechanical purchase and easy extrusion from bone, implant breakage, and potential for physeal damage and permanent closure. Recently, an alternative device to Blount staples called the eight-Plate (Orthofix, McKinney, Texas) has been presented for hemiepiphysiodesis and guided growth. Their theoretical advantages over Blount staples include higher stability, faster correction of the deformity, and fewer complications.We performed a study in a pig model to compare the rate of angular deformity correction and implant extrusion after hemiepiphysiodesis with Blount staples and eight-Plates. In all animals, medial hemiepiphysiodesis was performed in the right proximal tibia with the eight-Plate and the left proximal tibia with the Blount staple. The medial slope angle, medial tibial plateau angle, proximal implant angle, distal implant angle, and distance of the body of the implant from the medial tibial cortex were measured on radiographs of the knee joints performed every 4 weeks. The angles of correction showed statistically significantly earlier effect on physeal guided growth of the eight-Plates compared to the Blount staples. Implant displacement/extrusion was statistically significantly lower for the eight-Plate. In this animal model, eight-Plates are significantly more effective than Blount staples for guided growth after temporary hemiepiphysiodesis.

Metal Backing Significantly Decreases Tibial Strains in a Medial Unicompartmental Knee Arthroplasty Model

Clinical success of unicompartmental knee arthroplasty (UKA) is on the rise and is dependent on multiple patient, implant, and surgical factors. Tibial subsidence has been clinically reported as a cause of failure in UKA with an all-polyethylene tibial design in the absence of metal backing, yet the role of metal backing UKA tibial components on tibial loading is not fully understood. In this study, composite tibiae were implanted with medial all-polyethylene fixed-bearing or metal-backed UKA tibial components and a 1.5-kN load applied in 3 different contact positions simulating femoral translation during gait. All-polyethylene tibial components exhibited significantly higher strain measurements in each femoral position. This study demonstrates the role that metal backing plays on generating an even loading distribution while diminishing the development localized regions of excessive loading across the medial tibial cortex.

The relationship of the medially-offset stem of the tibial component to the medial tibial cortex in total knee replacements in Korean patients

We examined the placement of the stem in relation to the medial tibial cortex when using total knee replacements (TKRs) with medially-offset tibial stems in Korean patients. Measurements were performed on the pre- and post-operative radiographs of 246 osteoarthritic knees replaced between January 2005 and May 2006 using the Genesis II or E-motion TKR with a medially-offset stem. Pre-operatively, we measured the distance between the mechanical axis and that of the tibial shaft and post-operatively, that between the midline of the tibial stem and the axis of the shaft. Knees were identified in which there was radiological contact between the tip of the stem and the medial tibial cortex. The mechanical axis was located medial to the axis of the shaft in 203 knees (82.5%). Post-operatively, the midline of the tibial stem was located medial to the tibial shaft axis in 196 knees (79.7%). In 16 knees (6.5%) there was radiological contact between the tibial stem or cement mantle and the medial tibial cortex. Our study has shown that the medially-offset stem in the tibial component may not be a good option for knees undergoing replacement for advanced osteoarthritis in some Korean patients.

A New Technology for Reducing Shear and Friction Forces on the Skin: Implications for Blister Care in the Wilderness Setting

It is well known that physical trauma to skin caused by repetitive friction is a primary component of blister formation. Although friction blisters in a wilderness setting particularly occur on the feet and ankles, they often form on the hands and fingers during such activities as white-water rafting, kayaking, and canoeing. These blisters are often incapacitating and can have disabling consequences. This article describes laboratory and clinical experiments testing the efficacy of a new bandage technology in reducing shear and friction forces on the skin. A custom-made apparatus was used in a laboratory setting to measure and compare the surface coefficient of friction of 11 bandages. In addition, a controlled clinical study was conducted on 15 healthy, able-bodied female subjects (mean age 35 years), where the same apparatus was used to measure the coefficient of friction of the skin over the medial tibial cortex with and without the new technology device in place. This laboratory study demonstrated the new device to have the lowest surface coefficient of friction of any bandage tested (0.57). For example, the common product Moleskin was 21% higher (0.67), with all other products testing at least 64% higher (>0.94). In the clinical study, the new technology device reduced the coefficient of friction on the skin by 31% (0.225 vs. 0.327), and this difference was statistically significant (P < .001). A bandage containing a new technology demonstrated the lowest surface coefficient of friction of any bandage tested. In addition, clinical tests performed with the same bandage demonstrated significant reduction of the coefficient of friction on the skin.

Tibial plateau stress fracture: A complication of unicompartmental knee arthroplasty using 4 guide pinholes

Unicompartmental knee arthroplasty has gained popularity recently as a treatment for unicompartmental tibiofemoral non inflammatory arthritis. Tibial plateau stress fracture after unicompartmental knee arthroplasty (UKA) through guide pin holes placed in the proximal tibia has not been previously reported. In each case in this report, the compressive strength of the proximal tibia was reduced by the drilling of multiple holes for the placement of guide pins and holes for the lugs of the tibia component resulting in fracture through these holes between 3 and 18 weeks (median 8 weeks) post-operatively. In at least one case, the medial tibial cortex was violated by one pin. All cases required revision total knee arthroplasty (TKA). It is intuitive to caution against the use of multiple guide holes in the proximal tibia in UKA. If 3 or more hole pins are deemed necessary, surgeons must be aware of the potential for stress fracture and monitor patients accordingly. Peripheral pins that infract the medial tibial cortex should also be avoided.

Salvage technique for treatment of periplafond tibial fractures: the modified fibula-pro-tibia procedure.

We describe a technique of fixation for treatment of distal tibia periplafond fractures and nonunions that uses a modification of the principle of the fibula-pro-tibia procedure (fusing the tibia and fibula together to create a one-bone lower leg). The fibula is plated, and the screws are brought across to the medial tibial cortex. The procedure is accomplished with or without a tibial buttress plate and always includes iliac crest bone grafting of the nonunion site and synostosis. We have used this technique in five patients with satisfaction.

Valgus osteotomy of the tibia with a Puddu plate combined with anterior cruciate ligament reconstruction

Anterior knee instability associated with a varus deformity is a complex condition with several treatment possibilities. Among these, anterior cruciate ligament (ACL) associated to a simultaneous valgus tibial osteotomy is a increasing indication. This simultaneous procedure adds technical issues to those related to the isolated surgeries. Thus, the osteotomy plane and location of fixation hardware shouldn’t conflict with tibial tunnel and ACL graft fixation. Authors analyze the relations between a opening tibial valgus osteotomy stabilized with a Puddu plate and ACL reconstruction with a patellar tendon graft fixated with interference screws in 10 human cadaver knees. A straight oblique tibial osteotomy starting on the medial tibial cortex and oriented laterally and proximally was performed on all knees with a 10mm opening medially and stabilized with a Puddu plate on the most posterior aspect of the medial tibia, and a tibial tunnel drilled 50° to tibial plateau. With this technique there was no intersection between tibial tunnel or interference screw and the osteotomy or the plate fixation screws.

Evaluation of a free vascularized medial tibial bone graft in dogs.

To develop a free vascularized tibial bone graft based on the periosteal saphenous blood supply. Preliminary anatomic study of medial tibial blood supply. In vivo comparison of a vascularized and avascular tibial bone graft. Nine canine cadavers; 14 healthy adult dogs that weighed 25 to 32 kg. An anatomic study of the vascular supply of the medial aspect of the tibia was performed using the Spalteholz technique. A bone graft consisting of the medial aspect of the tibia was transferred to a mandibular defect as a vascularized graft in 7 dogs and as an avascular graft in 7 dogs. Bone scans were performed to evaluate graft perfusion. Radiographic evaluation of the mandibles and tibias was performed. The dogs were killed after 60 days, five mandibles from each group were examined histologically, and two from each group were evaluated using the Spalteholz technique. The saphenous vascular pedicle provides vascular perfusion to the medial tibial cortex. Bone scans and radiographic evaluations were consistent with viable bone in the vascularized grafts, and nonviable bone in the avascular grafts. Histological examination revealed live, healing bone in vascular grafts and necrotic bone in avascular grafts. Spalteholz evaluation revealed many small arborizing vessels in the vascular grafts and no organized vasculature in the avascular grafts. The vascularized medial tibial cortical bone graft survived and proceeded to bony union in the mandibular body defect more readily than the avascular graft in this experimental model. A vascularized medial tibial bone graft is a suitable free graft for use in reconstructing bone defects in dogs.

Tibial antivarus closing wedge osteotomy

Antivarus lateral closing wedge osteotomy of the proximal tibia is a time-tested surgical technique. Redistribution ofweight-bearing forces within the knee joint decreases the medial compartment load and the varus knee moment. Young or middle-aged patients as well as athletes with medial unicompartmental arthritis, posterolateral instability and varus thrust, or chronic anterior cruciate ligament deficiency and varus malalignment may be candidates. The indications have expanded recently to include patients with a varus mechanical axis who are undergoing periosteal resurfacing, autogenous chondrocyte implantation, meniscal transplantation, osteochondral grafting, or multiple subchondral bone microfractures. The osteotomy is performed between the knee joint and the tibial tubercle by removing a laterally based bone wedge. The construct is stable because of osteoclasis of the medial tibial cortex, an intact periosteal hinge, and excellent apposition of broad cancellous bone surfaces. Early knee motion is possible and bone healing is expeditious. Complications can be averted by careful patient selection, precise preoperative planning, and meticulous surgical technique. The weight-bearing line method uses a full-length standing radiograph to determine the desired correction angle. The osteotomy is performed with fluoroscopic guidance through a limited exposure. Low-profile step staples provide satisfactory fixation, and no bone grafting is required. Tibial Antvarus lateral closing wedge osteotomy is a useful and reliable surgical technique.

Tibial tunnel enlargement after anterior cruciate ligament reconstruction by autogenous bone-patellar tendon-bone graft.

This retrospective study was designed to evaluate changes in the diameter of the tibial tunnel over time following the reconstruction of the anterior cruciate ligament (ACL) with a bone-patellar tendon-bone autograft in 44 patients. The changes in the geometry of the bone tunnels were measured radiographically during the immediate postoperative period and at time intervals between 3 and 36 months after surgery. The dimensions at 1 year were correlated with the 1-year clinical results. The distance between the sclerotic margins of the tibial tunnel was measured at the distal tunnel exit on the medial tibial cortex, in the middle of the tunnel, and proximally at the level of the joint line. The dimensions were calculated by using a magnification factor determined by reference to the interference screw of known diameter located within the tunnel. The position of the centre of the tibial tunnel with regard to Blumensaat's line was also measured. The average tunnel diameter at the proximal tibial exit increased from 12 +/- 1.9 mm (mean +/- standard deviation) postoperatively to 14 +/- 2.2 mm at 3 months. The average proximal tunnel diameter did not significantly change from 3 months to 2 years, and then decreased to 13 +/- 2.4 mm at 3 years. At 1 year, most of the patterns of osteolysis were of the cone type (57%), followed by the cavity type (40%) and line type (3%). The degree of osteolysis was not related to the tibial tunnel position with respect to Blumensaat's line. There was no correlation between the changes in tunnel diameter and either the IKDC score or the residual joint laxity measured by a KT-100 arthrometer. The aetiology of tunnel enlargement is currently unknown. Possible factors responsible for bone resorption include micromotion of the graft relative to the tunnel wall, leading to an inflammatory response in the tunnel, or stress shielding of the tunnel wall proximal to the interference screw.