Medial Proximal Tibia Research Articles

The efficacy of guided growth as an initial strategy for Blount disease treatment.

PurposeThe aim of this study was to evaluate the success of guided growth by temporal hemiepiphysiodesis of the lateral proximal tibia as a first line treatment option for Blount disease.MethodsThis was a retrospective multicentre study conducted in five centres, covering data on 55 limbs in 45 patients, with an average follow-up of 24.5 months following plate insertion. Preoperative alignment analysis was compared with three measurements taken postoperatively. The normalization of the mechanical medial proximal tibia angle (mMPTA) was defined as the primary outcome measure.ResultsMean age at surgery was 9.5 years. Average preoperative mMPTA was 77°. On average, at 24.5 months post-surgery, mMPTA was 86.33°, while 43/55 limbs (78.18%) have achieved normalization (mMPTA 85° to 90°). Average rate of correction was 1° per month. When grouping the children as infantile (11 limbs), juvenile (12 limbs) and adolescent (32 limbs), operated on before the age of four years, between four and ten years and after the age of ten years, respectively, 63.63%, 66.67%, 87.5% have completed correction of deformity during the follow-up period. Interestingly, the femoral component of the deformity has achieved correction as well in 33/55 limbs (64%).ConclusionHemiepiphysiodesis is an effective first line treatment for Blount disease. Overall success rate is good but varies according to child’s age. Adolescent Blount has the best chance of achieving full correction while same treatment is less effective in infantile Blount.Level of evidence: IV

Isolated high tibial osteotomy is appropriate in less than two-thirds of varus knees if excessive overcorrection of the medial proximal tibial angle should be avoided

PurposeTo perform a detailed deformity analysis of patients with varus alignment and to define the ideal osteotomy level (tibial vs. femoral vs. double level) to avoid an oblique joint line.MethodsA total of 303 digital full-leg standing radiographs of patients aged 18–60 years and varus alignment [mechanical tibiofemoral varus angle (mFTA) ≥ 3°] were included. All legs were analyzed regarding mFTA, mechanical medial proximal tibia angle (mMPTA), mechanical lateral distal femur angle (mLDFA), and joint line convergence angle. Based on mFTA, varus alignment was categorized as “mild” (3°–5°), “moderate” (6°–8°), or “severe” (≥ 9°). Deformity location was determined according to the malalignment test described by Paley. Two osteotomy simulations were performed with different upper limits for mMPTA: anatomic correction (mMPTA ≤ 90°, mLDFA ≥ 85°) and overcorrection (mMPTA ≤ 95°, mLDFA ≥ 85°). If a single osteotomy exceeded these limits at the intended mFTA of 2° valgus, a double-level osteotomy was simulated. If even a double-level osteotomy resulted in deviations from the defined limits, the leg was categorized as “uncorrectable”.ResultsMean mFTA was 6° ± 11° of varus (range 3°–15°). A tibial deformity was observed in 28%, a femoral deformity in 23%, a combined tibial and femoral deformity in 4%, and no bony deformity in 45%. The prevalence of a tibial deformity did not differ between varus severity groups, whereas a femoral and bifocal deformity was significantly more prevalent in knees with more distinct varus (p < 0.001). Osteotomy simulation revealed that isolated high tibial osteotomy (HTO) was appropriate in only 12% for anatomic correction, whereas a double-level osteotomy was necessary in 63%. If overcorrection of mMPTA was tolerated, the number of HTOs significantly increased to 57% (p < 0.001), whereas the number of double-level osteotomies significantly decreased to 33% (p < 0.001). Isolated DFO was considered ideal in 8% for both simulations. Significantly more knees were considered “uncorrectable” by simulating anatomic correction (18 vs. 2%; p < 0.001). A double-level osteotomy was significantly more often necessary in knees with “severe” varus (p < 0.001).ConclusionLess than one-third of patients (28%) with mechanical varus ≥ 3° have a tibial deformity. If anatomic correction (mMPTA ≤ 90°) is intended, only 12% of patients can be corrected via isolated HTO, whereas 63% of patients require a double-level osteotomy. If slight overcorrection is accepted (mMPTA ≤ 95°), 57% of patients can be corrected via isolated HTO, whereas 33% of patients would still require a double-level osteotomy.Level of evidenceIII, cross-sectional study.

CORR Synthesis: Can Guided Growth for Angular Deformity Correction Be Applied to Management of Pediatric Patellofemoral Instability?

CORR Synthesis: Can Guided Growth for Angular Deformity Correction Be Applied to Management of Pediatric Patellofemoral Instability?

Mobile bearing leads to less proximal medial tibial strain following UKA in comparison with fixed bearing in a cadaver setup

Aims and Objectives:Inexplicable pain to the medial proximal tibia is a frequent finding leading to revision after unicondylar knee arthroplasty (UKA). This study is an effort to find out, if there are any differences between mobile (MB) and fixed bearing (FB) UKA designs in terms of resulting strain in the medial proximal tibia as measured in an in vitro cadaver setup. It was hypothesized that MB UKA would result in lower bone strain.Materials and Methods:Five pairs of fresh-frozen full leg cadaver specimens were mounted in a kinematic rig that applied a dynamic squatting motion knee flexion after prior 3D CT. The rig allowed for 6 degrees-of-freedom at the knee while forces were applied to the quadriceps and hamstrings. During testing, an infrared camera system tracked the location of reflective markers attached to the tibia and femur with bicortical bone pins. Tibial cortical bone strain was measured with stacked strain gauge rosettes attached at predefined anterior and posterior positions on the medial cortex. Sensor outputs were recorded at 2000 Hz and synchronized with kinematic data prior and after pairwise implantation of MB and FB UKA directly comparing those between left and right knees from the same donor.Results:Bone strain values consistently increased with increasing flexion angle. FB UKA significantly increased strain in the anterior region of the medial tibial bone, while MB closely replicated strain values of the native knee.Conclusion:Proximal tibial bone strain seems to be lesser following MB UKA in comparison with FB UKA. Clinical studies will have to show, if this translates into a higher rate of pain problems with FB UKA.

Articular surface of the medial proximal tibia is aligned parallel to the ground in three-dimensional space under weight-bearing conditions for healthy and osteoarthritic knees

Purpose: The inclined articular surface in the medial compartment of the proximal tibia (MCT) is an important factor for varus knee osteoarthritis (OA). It is assumed that the MCT in advanced knee OA is aligned parallel to the ground in the coronal plane under weight-bearing (WB) conditions (parallel phenomenon) by keeping the WB line vertical to the ground. To accurately assess the parallel phenomenon of MCT, the normal vector of the approximation plane in a 3D space should be applied. This study aimed to prove the parallel phenomenon of MCT in a 3D space under WB conditions, using the normal vector for the approximation plane of MCT in osteoarthritic knees, compared with that in healthy knees.

Comparison of intraoperative fluoroscopy and postoperative CT measurement of mounting parameters for Taylor Spatial Frame

Objective To investigate the accuracy and postoperative efficacy of fluoroscopy and CT in measuring the mounting parameters of Taylor Spatial Frame. Methods Data of patients with peripheral knee deformities who were treated by Taylor Spatial Frame from June 2006 to December 2017 were retrospectively analyzed. According to different measurement methods of mounting parameters, they were divided into fluoroscopy group (mounting parameters were obtained by intraoperative fluoroscopy) and CT group (mounting parameters were obtained by postoperative CT). There were 33 patients (35 segments) in the fluoroscopy group, 23 males (23 segments) and 10 females (12 segments), with an average age of 36.4±11.6 years old. In CT group, there were 30 patients, 19 males and 11 females, with an average age of 36.9±13.8 years. There were 22 cases (24 segments) of high tibial osteotomy, 5 cases (5 segments) of distal femur osteotomy, and 6 cases (6 segments) of both distal femur and high tibial osteotomy. Operation time, external fixation time, the number of electronic prescription and deformity correction time, mechanical axis deviation (MAD), medial proximal tibia angle (MPTA), mechanical lateral distal femoral angle (mLDFA), range of motion (ROM) andhospital for special surgery (HSS) knee functional scores were compared between the two groups. Results All the 63 patients were followed up for 21.9 months (range, 12-60 months). In fluoroscopy group, operating time was 100.9±9.1 min, electronic prescription number 1.4±0.6, and deformity correction time was 19.4±3.6 days. In CT group, operating time was 79.2±10.8 min, electronic prescription number 1.2±0.4, and deformity correction time was 16.0±4.4 days. The difference of the above indexes between the two groups was statistically significant (t=8.803, 2.042, 3.440, all P 0.05). In the fluoroscopy group, 22 segmental deformities were corrected by one electronic prescription, and 13 segmental deformities were corrected by two or more electronic prescriptions. In CT group, 25 segmental deformities were corrected by one electronic prescription, and 5 segmental deformities were corrected by two electronic prescriptions. There was no incision infection and no neurovascular injury in the two groups. Conclusion Both fluoroscopy and CT scan can obtain the mounting parameters of the Taylor Spatial Frame, and the results of correction of the peripheral deformities of the knee joint are satisfactory. However, CT measurement of the mounting parameters is more accurate which could achieve shorter operation time, and less times of electronic prescriptions. Key words: Knee joint; Musculoskeletal abnormalities; Fluoroscopy; Tomography, spiral computed; External fixators

Denosumab prevents periprosthetic bone mineral density loss in the tibial metaphysis in total knee arthroplasty

BackgroundPeriprosthetic bone quality is one of the most important factors preventing early prosthesis migration and long-term failure. Although denosumab, which binds to the receptor activator of nuclear factor kappa-B ligand (RANKL), has been linked with periprosthetic bone mineral density (BMD), the effectiveness of denosumab against bone loss remains unclear. We hypothesized that denosumab treatment after total knee arthroplasty (TKA) could prevent periprosthetic bone resorption. MethodsIn this prospective cohort study, 28 patients with primary knee osteoarthritis were divided into two groups: denosumab (denosumab and vitamin D) and control (vitamin D only) groups. All patients underwent TKA with the same implant model and received medication after surgery. We used dual-energy X-ray absorptiometry to measure periprosthetic BMD after TKA. ResultsIn the control group, the BMD of the proximal medial tibia decreased drastically at 12 months after TKA (−19.7%). Denosumab treatment significantly preserved this BMD loss (0.7%). The linear regression analysis revealed that denosumab intervention had the highest significantly positive relationship with BMD. ConclusionsOur results indicate that denosumab treatment significantly reduces periprosthetic BMD loss, even at the early stages after TKA. This therapeutic strategy may facilitate early stable fixation of the prosthesis which, in turn, may help to prevent early implant migration and reduce the need for revision surgery.

Factors affecting the outcome in the correction of angular deformities around the knee using extraperiosteal tension band plate: A local experience

Objectives: The aim of this study is to reflect on our local experience with extraperiosteal tension band plate around the knee and the factors that affect the outcome. Methods: This is a retrospective review of 21 patients (34 limbs) and involving 35 segments gathered and treated during a period from 2007 to 2018 by a single surgeon employing a standardized technique. The inclusion criteria were all patients with coronal plane deformities around the knee with an open physis, regardless of pathological background. Patients who had previous or concurrent surgeries for the same problem were excluded from the study. Patients' age and body mass index were recorded. Mechanical axis deviation (MAD) distance, tibio-femoral (T-F) angle, mechanical lateral distal femoral angle, and mechanical medial proximal tibia angle were measured from a standing anteroposterior radiograph. Results: The average age was 6.5 years, and the mean duration of treatment was 13.6 months, with “sick physis” requiring longer durations. The mean rate of correction of T-F angle was 1.5°/month. The MAD distance improved at an average rate of 2.4 mm/month. The distal femur physis improved at a rate of 0.69°/month, while the proximal tibia physis improved at a rate of 0.58°/month. Conclusion: The severity of preoperative deformity influenced the rate of correction, and this is further influenced by the pathological background and physis treated, femora faster than tibiae. Patients with more than 3 years of growth remaining showed faster correction.

Lower extremity alignment due to patellofemoral syndrome and dynamic postural balance

This study is a prospective study. Lower extremity malalignment is an important etiologic factor in patellofemoral pain syndrome (PFPS). We hypothesized that lower limb malalignment may affect dynamic balance and physical function. This prospective study was conducted to investigate the relationship between the lower limb alignment and the dynamic balance and physical function in patients with PFPS. The study included 62 individuals with unilateral PFPS. Pain severity was assessed by the numerical pain scale and the pain duration was recorded. Lower extremity bone alignment was evaluated by the lateral distal femoral angle (LDFA) and the medial proximal tibia angle. Dynamic postural balance was assessed by the star excursion balance test. The functional status of the patients was evaluated by the 30-second chair stand test. The mean duration of the pain was 24.2 ± 31.5 months and the mean pain severity was 8.1 ± 1.4. Although there was a significant difference found between the affected and unaffected LDFA values of lower extremities (p < 0.05), there was no difference found with regard to the dynamic balance values of the lower extremities (p > 0.05). However, significant changes of posterolateral balance were identified at a painful side without causing a postural dynamic imbalance (p < 0.05). In our study, we found a valgus deformity as a deterioration in the lower limb alignment of patients with PFPS which may cause a deterioration of posterolateral balance only. However, no change in postural dynamic balance was observed in the comparison of affected side and unaffected side. Dynamic postural balance has been influenced by many kinematic changes related to lower extremities including pelvis, hip, and ankle. Thus, reciprocal mechanisms in the anatomical structures may compensate the postural balance dynamically.

Articular surface of the medial proximal tibia is aligned parallel to the ground in three-dimensional space under weight-bearing conditions in healthy and varus osteoarthritic knees.

To test the hypothesis that an inclined articular surface on the medial proximal tibia is aligned more parallel to the ground in three-dimensional (3D) space under weight-bearing (WB) conditions (parallel phenomenon) than under non-WB (NWB) conditions in healthy and varus osteoarthritic knees. We examined 55 healthy knees (26 women, 29 men; mean age, 70 ± 6years) and 108 varus osteoarthritic knees (66 women, 16 men; mean age, 74 ± 7years). For the evaluation under WB conditions, a 3D assessment system was used on biplanar long-leg radiographs and 3D bone models using a 3D-to-2D image registration technique. In addition, the least square method was used to determine the approximation plane. The angles between the normal vector for the approximation plane of an articular surface on the medial proximal tibia and each axis of the tibial or world coordinate system were calculated. Morphologically, the inclination of the approximation plane was steeper in osteoarthritic knees than in healthy knees (p < 0.0001). The approximation plane was aligned more parallel to the ground under WB conditions than under NWB conditions in healthy (p < 0.0001) and osteoarthritic knees (p < 0.0001). The parallel phenomenon in the medial proximal tibia was confirmed for healthy and varus osteoarthritic knees. The medial proximal tibia plays an important role in the parallel phenomenon, assumingly associated with varus alignment and varus thrust. The inclination of the medial proximal tibia may become a new parameter for imaging investigations. III.

The entry point of intramedullary tibia cutting guide should vary according to the individual tibia morphology in TKA.

In total knee arthroplasty (TKA) using the intramedullary tibial cutting guide (IMTCG), the positioning of the IMTCG is important for accurate tibial bone resection. The aim of this study was to evaluate the ideal entry point of IMTCG and affecting radiologic factors. From May 2017 to February 2018, 91 consecutive TKAs for osteoarthritis were included. From preoperative full-length radiographs, we measured the medial proximal tibia angle (MPTA), lateral distal tibia angle (LDTA), tibial bowing angle (TBA), medial to lateral width of the tibial plateau, tibial length, and ideal coronal entry point. In preoperative short knee lateral radiographs, we measured the anterior to posterior length of the tibial plateau, tibial posterior slope angle (TPSA), metaphysio-diaphyseal angle (MDA), and ideal sagittal entry point. The ideal coronal and sagittal entry points were defined as the points crossing the tibial plateau and tibial anatomical axis on the coronal and sagittal radiographs, respectively. The ideal entry point was 51.4 ± 4.3% (SD) from the medial margin and 27.0 ± 5.8% (SD) from the anterior margin of the tibial plateau. However, the range varied from 39.8 to 60.5% on the coronal plane and from 9.6 to 37.7% on the sagittal plane, respectively. As the MPTA (rho = -0.490) and TBA (rho = -0.433) were increased, the coronal entry point moved medially. As TPSA (rho = -0.761) and MDA (rho = -0.495) were increased, the sagittal entry point moved anteriorly. The ideal entry point of IMTCG should vary according to the individual tibial morphology.

Coronal malalignment of lower legs depending on the locations of the exostoses in patients with multiple hereditary exostoses

BackgroundsThough malalignment of lower legs is a common pathologic phenomenon in multiple hereditary exostoses (MHE), relationship between locations of exostoses and malalignment of lower legs remains unclear. This study examined radiographs of MHE patients in an attempt to evaluate the tendency of coronal malalignment of lower legs with different location of exostoses on lower legs consisting of two parallel long bones.MethodsBetween 2000 and 2017, we retrospectively reviewed the anteroposterior films of the teleo-roentgenographics of 63 patients with MHE. The patients were classified into four different groups depending on the locations of the exostosis, which occurred on both proximal and distal tibiofibular joints (A), proximal tibiofibular joint (B), distal tibiofibular joint (C), and not for the tibiofibular joint area (D). To evaluate the influence of the location of exostoses on coronal malalignment of lower legs, medial proximal tibia angle (MPTA), lateral distal tibia angle (LDTA), and fibular shortening were analyzed for each group.ResultsSignificant difference was observed in multiple comparative analyses for each of the four groups. On MPTA radiologic analysis, group A showed greatest value with significant difference compared with groups C and D (vs. (B): p = 0.215; vs. distal joints (C): p = 0.004; vs. (D): p = 0.001). Group B showed significant difference only with group D (vs. distal joints (C): p = 0.388; vs. (D): p = 0.002), but for group C and D showed no significant difference. For LDTA, only group A showed significant difference compared to other groups (p < 0.001). With regard to tibiofibular ratio for evaluation of fibular shortening, group A showed the lowest ratio (vs. (B): p = 0.004; vs. (C): p = 0.655; vs. (D): p < 0.001). Group C also presented the significant lower ratio than group D (p = 0.002).ConclusionsFor evaluation of the coronal malalignment of lower legs in MHE patients, not only ankle around the distal tibiofibular joint but also proximal tibiofibular joint should be examined, in that, lower limb deformity occurred by two parallel long bone which has self-contained joint.Level of evidenceLevel III, retrospective comparative study.

Assessment of valgus laxity after release of the medial structure in medial open-wedge high tibial osteotomy: an in vivo biomechanical study using quantitative valgus stress radiography

BackgroundTo perform medial open-wedge high tibial osteotomy (OWHTO), surgeons expose the medial-proximal tibia by releasing or cutting the superficial layer of the medial collateral ligament (sMCL). Biomechanically, the sMCL provides primary restraint against valgus forces. Therefore, any release of the sMCL can cause valgus instability of the knee joint. The purpose of this study was to assess valgus laxity after release of the medial structure of the knee during OWHTO.MethodsBetween 2009 and 2015, 84 consecutive patients (93 knees) who underwent OWHTO using a locking plate were enrolled in this study. All patients underwent radiological examinations before surgery, during surgery, 1 year after surgery, and after plate removal to objectively assess valgus laxity. The medial joint space (MJS) and the joint line convergence angle (JLCA) of the knee were evaluated using quantitative valgus stress radiography. Clinical evaluation was performed 2 years after surgery.ResultsThe mean functional knee score improved significantly, from 65.5 to 91.1 points (p < 0.0001). The mechanical axis percentage shifted to pass through a point 69.7% lateral from the medial edge of the tibial plateau. The MJS and JLCA increased significantly during OWHTO surgery (11.0 mm, 7.4 °, p < 0.0001). However, no significant differences were noted in the MJS and JLCA among preoperative, 1-year postoperative periods and after plate removal.ConclusionValgus laxity was significantly greater after release of the sMCL. However, no significant differences were noted in valgus laxity in preoperative, 1-year postoperative periods and after plate removal. Complete release of the sMCL did not cause postoperative valgus laxity after OWHTO surgery.Trial registrationTrial registration number: No.012–0360.

Insight into the possible aetiologies of Blount's disease: a systematic review of the literature.

Blount's disease or bowed leg deformity, is a unilateral or bilateral growth deformity of the medial proximal tibia that leads to a tibial varus deformity. A distinction can be made in an early and late onset type. The disease seems to have a predisposition for certain descends. Since the first publication of Blount's disease, different hypotheses on the aetiology are proposed but no consensus exists. The objective of this study is to provide an overview of the available hypotheses on the aetiology of Blount's disease since its first description and assessment of the available level of evidence, the quality of evidence and the occurrence of bias supporting these individual hypotheses. A systematic search according to the PRISMA statement was conducted using PubMed, MEDLINE, EMBASE and the Cochrane Library using a broad combination of terminology to ascertain a complete selection. Proper MESH search criteria were formulated and the bibliographic search was limited to English and Dutch language articles. Articles with no mention of aetiology or a disease related to Blount's were excluded. Level of evidence and types of bias were assessed. Thirty-two articles that discuss the aetiology of Blount's disease were selected. A variety of hypotheses was postulated in these articles with most research in the field of increased mechanical pressure (obesity, early walking age) and race (descend). Blount's disease most likely has a multifactorial origin with influence of genetic and racial predisposition, increased mechanical pressure on the growth plate as a consequence of obesity or early walking age and possibly also nutrition. However, the exact aetiology remains unclear, the probable explanation is that multifactorial factors are all contributing to the development of Blount's disease. Histological research has shown that a disorganization of bone and cartilage structures on the medial side of the proximal tibial physis is present in patients with Blount's disease. Based on the available evidence on the aetiology of Blount's disease, we conclude that it is multifactorial. Most papers focus only on one hypotheses of Blount's disease occurrence and all are characterized as low level of evidence. There seems to be a preference for certain descends. Further research on especially genetic predisposition is needed to provide more insight in this factor of Blount's disease.

The influence of femoral and tibial bony anatomy on valgus OA of the knee.

Approximately 10% of all patients that require a total knee arthroplasty present with valgus osteoarthritis (OA) of the knee. Valgus OA goes along with posterolateral bone loss and lateral soft tissue tightness. The role of malalignment on the development of OA is not fully understood. The current study investigates whether the femoral offset (FO), femoral mechanical-anatomical (FMA) angle, anatomical lateral distal femur angle (aLDFA), mechanical lateral distal femur angle (mLDFA), medial proximal femur angle (MPFA), medial proximal tibia angle (MPTA) or lateral distal tibia angle (LDTA) differ in patients with valgus OA of the knee. FO, FMA angle, aLDFA, mLDFA, MPFA, MPTA and LDTA were assessed and compared between 100 consecutive knees with minimal valgus OA (50 male, 50 female) and 100 consecutive knees with minimal varus OA (50 male, 50 female). FO was significantly higher in males with valgus OA (p = 0.002) and females with varus OA (p = 0.01). The observed values for the FMA angle were significantly higher in males with valgus OA (p = 0.002) and females with varus OA (p = 0.041). The aLDFA and mLDFA were significantly smaller in all patients with valgus OA (p < 0.001). No differences between the varus and valgus groups were detected regarding MPFA (males: p = 0.052; females: p = 0.719). Tibial measurements showed significantly higher values for the MPTA (p < 0.001) in both valgus groups and no difference for LDTA (men: p = 0.139; women: p = 0.196). Bony alterations in the femoral anatomy seem to be more important than in the tibial anatomy. While in male patients with valgus OA, the main anatomic variation is the hypoplasia of the lateral femoral condyle, in females both decreased femoral offset of the hip as well as hypoplasia of the lateral condyle are present. III.

Intraosseous Catheter Flow Rates and Ease of Placement at Various Sites in Canine Cadavers.

Objective: To compare intraosseous catheter placement difficulty, success rates, and flow rates at four different locations in canine cadavers.Design: Prospective study.Setting: Private referral center.Animals: Eleven fresh canine cadavers.Interventions: With owner consent, animals presenting for euthanasia were recruited. Animals received heparin (1,000 IU/kg IV) at least 5 min prior to euthanasia. After euthanasia, EZIO intraosseous catheters were placed into the ilial wing, proximal medial tibia, proximal lateral humerus, and distal lateral femur on one side of the animal. Time to catheter placement and catheter difficulty were scored for each placement site. Sterile saline was infused into each location simultaneously over 5 min, first via gravity then using 300 mmHg pressure. Animals were repositioned onto the contra-lateral side and the experiment repeated.Measurements and Main Results: Placement was successful in 16/22 ilial, 18/22 tibial, and 22/22 femoral and humoral attempts. A post-hoc analysis revealed the ileum had a significantly greater difficulty score when compared to the femur and humerus (p ≤ 0.0001). The femur had a statistically significant faster placement time when compared to the ileum (p ≤ 0.05). Gravity infusion rates were statistically lower in the tibia when compared to humerus (p ≤ 0.01) and between the tibia when compared to the femur (p ≤0.001). Additionally, pressurized infusion rates were statistically lower in the tibia compared to the humerus (p ≤ 0.0001), the femur (p ≤ 0.0001), and the ileum (p ≤ 0.01).Conclusions: The femur and humerus had high success rate for IO catheter placement and low placement time and difficulty scores. Pressurized intraosseous flow rates were highest in the humerus and femur. Contrary to human literature, success rates for catheter placement in the humerus and femur were higher than at other sites, suggesting the humerus and femur may be preferred sites for intraosseous catheter placement in the dog. Further investigation through a larger sample size is required to confirm these findings.

A combined prone and supine approaches for complex three column tibial plateau fracture with posterolateral articular injury

IntroductionUpdated three column fixation of tibial plateau fractures (TPFs) arouse the importance of posterior column articular reduction. Complex TPFs with posterolateral (PL) articular injury is difficult to manage. We presented a strategy of combined positions and approaches to treat these injuries. Surgical technique was described and outcome of these were reported. Materials and MethodsFrom 2014 Jan to 2016 Dec, there were 132 patients of TPFs treated in our institute. Preoperative evaluation included plain films and 2D/3D CT scan to evaluate the involvement of articular surface and associated columns. Inclusion criteria were three column TPFs with PL corner injury. We put patients in prone position first with reverse L incision to manage PL articular impaction and posteromedial (PM) fractures. Then we repositioned the patients in supine to treat anterolateral fixation. Postoperative radiographic analysis, physical examination findings, and patient reported outcome scores from the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire were recorded. ResultsPatient demographic information was retrospectively reviewed with a mean follow-up time of 34.4 months (range 24–48 months). The average time to union was 5.2 months (range 4-8months). 13/16 (81%) of patients had satisfactory articular reduction by plain films (less than 2 mm articular step off). All patients demonstrated healed without secondary displacement or infection. All patients demonstrated satisfactory coronal (medial proximal tibia angle 84.68 degrees) and sagittal alignment (posterior proximal tibia angle 84.75 degrees). Condylar width averaged 3.93 mm. 3/16 (19%) of cases required posterolateral columnar plating in addition to posteromedial columnar plating. The knee range of motion averaged 115 degrees (ranged from 0 degrees of extension to140 degrees flexion). The average KOOS score was 83/100 (range 76–90). 3 patients in the series developed a surgical site superficial infection and resolved after debridement and oral antibiotics use. No patient eventually received total knee arthroplasty at the last follow up. ConclusionsOur strategy provides an effective method to treat three column tibial plateau fractures with PL articular injury.

Lower Limb Malrotation Is Regularly Present in Long-Leg Radiographs Resulting in Significant Measurement Errors.

Weight-bearing long-leg radiographs are commonly used in orthopaedic surgery. Measured parameters, however, change when radiographs are conducted in different rotational positions of the leg. It was hypothesized that rotational errors are regularly present in long-leg radiographs resulting in wrong measurements. In 100 consecutive long-leg radiographs conducted according to the method of Paley, rotation was assessed by fibular overlap. Angular parameters in radiographs (mechanical lateral proximal femoral angle (mLPFA), mechanical lateral distal femoral angle (mLDFA), angle between the anatomical and mechanical femoral axis (AMA), mechanical medial proximal tibia angle (mMPTA), mechanical lateral distal tibial angle (mLDTA), and the mechanical femoral and tibial axis (mFA-mTA) were measured and deviations related to malrotation calculated. An average internal rotation of 8 degrees was found in lower limbs showing a range between 29 degrees of internal and 22 degrees of external rotation. As a result, mean differences before and after rotational correction for measured parameters (mLPFA, mLDFA, AMA, mMPTA, mLDTA, mFA-mTA) ranged between 0.4 and 1.7 degrees (-2.1; 5.6 95% confidence interval [CI]). In conclusion, malrotation of lower limbs is regularly present in long-leg radiographs. As all measured parameters are influenced by malrotation, correct lower limb rotation needs to be verified.

Is it Friction? A Rare cause of Medial Knee Pain

HISTORY: A 22-year-old male with no significant past medical history presents with reports of two weeks of progressive medial knee pain, after beginning training for a sprint triathlon. Prior to starting his training, he primarily lifted weights and ran only sporadically. He increased his running significantly up to 3 to 4 miles 4 to 5 times per week. Pain was initially only present while running, but became present with any activity including swimming, especially with a frog-leg kick, after cycling, and finally with day-to-day walking. He notes mild swelling in the medial knee. He denies any catching, locking, buckling, or give-way of the knee. He denies any paresthesias in the right lower extremity. PHYSICAL EXAMINATION: Pain in the right medial knee with single leg squat on the right. No knee effusion, however, there is mild swelling located just below the medial joint line over the proximal medial tibia on the right. Knee range of motion is full bilaterally. Ligamentous exam stable. Pain with valgus stress testing at 30 degrees on the right without laxity. No tenderness over the medial or lateral joint lines. Tenderness to palpation over the proximal medial tibia a few centimeters distal to the joint line and over the MCL in this region. No tenderness to palpation over the proximal MCL or pes anserine bursa. DIFFERENTIAL DIAGNOSIS: 1. Medial tibial plateau stress reaction 2. Distal MCL sprain 3. Pes anserine bursitis TEST AND RESULTS: Plain radiographs: — No acute osseous abnormality. MRI right knee: — focal subcortical marrow edema within the medial aspect of the tibia 2.5cm below the joint line at the site of a bony protuberance compatible with prominent medial tibial cress — No fracture line, or soft tissue mass FINAL/WORKING DIAGNOSIS: Medial tibial crest friction syndrome TREATMENT AND OUTCOMES: 1. Voltaren gel and activity modification with cessation of cycling, and reduction in training volume, with reported improvement. 2. Patient wanted to return to training for a triathlon and ultrasound-guided corticosteroid injection, deep to the MCL over the tibial protuberance, was performed. 3. Patient reported complete resolution of pain immediately after injection that was maintained at 2 weeks. 4. Patient completed his sprint triathlon without development of pain and he was instructed to follow-up should his symptoms recur.

MON-499 Tumor Induced Osteomalacia: 68Ga-DOTATATE PET/CT Scan For Localization

Introduction: Tumor Induced Osteomalacia (TIO) is a rare condition and a notoriously difficult diagnosis to make due to lack of awareness and nonspecific symptoms. But it is a surgically curable disease, so it should not be missed. We are reporting a case of TIO in a patient with insufficiency fractures who was initially diagnosed as ‘severe osteoporosis’. Clinical Case: A 60-year-old female presented to the Metabolic Bone Disease Clinic at our institution for recurrent stress fractures of hip and femur. A recent DXA scan showed worsening of BMD at the spine and hip with T-scores of -5.0 and -4.3 respectively. She was taking calcium and vitamin D supplementation. She had previously taken Alendronate and stopped for unclear reasons. She was taking Denosumab at the time of her presentation to our clinic. She was found to have very low phosphorus level of 0.8 mg/dl. Osteomalacia was suspected, so we asked her to stop Denosumab. Phosphorus replacement was started and she remained hypophosphatemic with phosphorus levels <1 mg/dl despite increasing doses of phosphorus supplements. A 24-hour urine phosphorus and fractional excretion of phosphorus was inappropriately elevated. A diagnosis of hyperphosphaturic hypophosphatemia causing osteomalacia was made. A hereditary disorder such as X-linked hypophosphatemia was not considered because of lack of family history and onset at an adult age. FGF-23 was elevated and a diagnosis of TIO was made. We used 68Ga-DOTATATE PET/CT scan as our initial, and single test for functional imaging/identification of the culprit tumor. The scan showed uptake in the left proximal medial tibia. Anatomical imaging with MRI confirmed the lesion. She underwent surgery for excision of the tumor and fixation of the tibia. Pathology was consistent with phosphaturic mesenchymal tumor. During follow up, phosphorus levels normalized within one month of surgery. She is currently doing well without any symptoms and no new fractures. We plan to repeat DXA scan and perform periodic monitoring of phosphorus level. Conclusion: TIO is a paraneoplastic disorder caused by FGF-23 secreted by mesenchymal tumors. It results in decreased reabsorption of phosphorus from the proximal tubule of kidneys, causing hyperphosphaturia and subsequently hypophosphatemia leading to defective mineralization of bones. A high index of suspicion is needed to diagnose this rare disorder. Any patient with an insufficiency fracture or a new referral for osteoporosis should have phosphorus level checked. If the phosphorus level is low, renal tubular reabsorption of phosphorus should be evaluated by measuring 24-hour urinary excretion of phosphorus. The culprit tumor should be localized using advanced imaging modalities such as 68Ga-DOTATATE PET/CT scan.