Lateral hinge fracture delays healing of the osteotomy gap in opening wedge high tibial osteotomy with a beta-tricalcium phosphate block

BackgroundThe purpose of this study was to investigate the healing process of synthetic bone grafts in opening wedge high tibial osteotomy (OWHTO) and to identify the factors that affect bone healing in OWHTO. It was hypothesized that lateral hinge fracture (LHF) is associated with delayed bone healing after OWHTO with synthetic bone grafting.MethodsThe subjects included 350 knees of 283 patients who underwent OWHTO using two wedged blocks of beta-tricalcium phosphate (β-TCP) with 60% porosity. The healing of the osteotomy gap using a radiologic rating system for OWHTO with synthetic bone grafts and the presence of an LHF were assessed up to postoperative 24 months.ResultsLHFs were found in 49 knees (14%). The osteotomy gap showed slower progression of radiographic healing with an LHF than without an LHF (P < .05). In the knees with LHFs, initial radiographic change in the osteotomy gap was observed almost at the same time as healing of the LHF. Multivariate logistic regression analysis identified LHF as the factor preventing the progression of bone healing (OR = 46.78, P < .05).ConclusionsLHF is associated with delayed bone healing after OWHTO with synthetic bone grafting.     

Effects of lateral opening wedge and medial closing wedge distal femoral osteotomies on axial load stability

BackgroundThe stability of the current distal femoral osteotomy is insufficient for early weight bearing and bone healing. The purpose of this study was to test the stability of medial closing wedge- (MCW-) and lateral opening wedge-distal femoral osteotomies (LOW-DFO), which have improved with the recent advances in technology.MethodsWe used composite bone models with MCW-DFO, improved with biplanar osteotomy technique and a Tomofix™ MDF plate, or LOW-DFO improved with biplanar osteotomy technique, a Tomofix™ LDF plate, and a β-TCP bone substitute, BONISH® graft. A cyclic axial loading test was employed to evaluate the strain on a plate and hinge point. The breaking axial load was measured.ResultsTensile strain on the plate produced by cyclic axial loading was significantly lower for LOW-DFO (2.0 ± 0.8 MPa) than for MCW-DFO (3.9 ± 1.6 MPa, P < .05). Compressive strain on the hinge point produced by cyclic axial loading was lower for LOW-DFO (6.6 ± 2.9 MPa) than for MCW-DFO (7.7 ± 4.6 MPa,). The maximum breaking axial load was significantly higher for LOW-DFO (5511 ± 945 N) than for MCW-DFO (4303 ± 518 N, P < .05).ConclusionsLOW-DFO improved with recent advanced technology was superior to MCW-DFO improved with advanced technology in both cyclic axial loading test and breaking axial load test. This suggests that LOW-DFO facilitates earlier weight bearing and bone healing than does MCW-DFO.     

Analysis of the relationship between the morphology of the proximal tibiofibular joint and lateral hinge fracture in open wedge high tibial osteotomy

BackgroundOne of the complications of open wedge high tibial osteotomy is lateral hinge fracture, which causes delayed bone healing. In this study, we focused on the morphology of the proximal tibiofibular joint to clarify the influence of this morphology on the occurrence of lateral hinge fracture in open wedge high tibial osteotomy.MethodsThe proximal tibiofibular joint of 58 knees in 55 patients who underwent open wedge high tibial osteotomy was classified as either horizontal or oblique, depending on the morphology of the fibular head. Lateral hinge fracture of Takeuchi classification type II or III was defined as unstable lateral hinge fracture. We analyzed whether patient background and bone morphological factors, including the morphology of the proximal tibiofibular joint, were associated with the occurrence of unstable lateral hinge fracture.ResultsThe horizontal and oblique types were found in 34 and 24 knees, respectively. There was no difference in the percentage of hinge points within the safe zone between the horizontal and oblique types; however, there was a significant difference in the unstable lateral hinge fracture incidence between the two groups. Unstable lateral hinge fracture occurred in seven knees, mostly in patients with an oblique proximal tibiofibular joint. The factors associated with the occurrence of unstable lateral hinge fracture were analyzed using logistic regression analysis; the fibular head of the oblique type was a significant factor.ConclusionOpen wedge high tibial osteotomy for oblique-type proximal tibiofibular joints may be more likely to cause unstable lateral hinge fracture than the horizontal type.     

Factors affecting the disparity between preoperative planning and postoperative correction status in distal femoral osteotomy

BackgroundThe purposes of this study were to evaluate whether the planning method using the contralateral limb status is reasonable and to determine the disparity between the preoperative planning and actual postoperative correction status by analyzing lateral cortical hinge fractures (LCHFs) in patients who underwent distal femoral osteotomy (DFO).MethodsFrom 2014 to 2018, 31 cases undergoing DFO were evaluated. The patients were divided into two groups according to two preoperative planning methods. The disparity between the preoperative planning and the postoperative weight-bearing line (WBL) ratio and clinical scores were compared. Analysis was performed to determine the causes of the disparity by evaluating the osteotomy configuration, including that of LCHFs.ResultsThe disparity was observed in the WBL ratio assessment (P < 0.01). In the comparison between two groups, no statistically significant differences were found in the change of WBL ratio (P = 0.78) and postoperative clinical scores. The length of the osteotomy gap was only related to the disparity (R² = 0.22, P = 0.01), while no statistical significance was found for the regression equation of the displaced LCHF (P > 0.05). The length of the remaining bone between the osteotomy end and opposite cortex was significantly associated with the presence of LCHF (odds ratio, 3.904).ConclusionsThe planning method using a contralateral limb status showed similar results to the classical method, but the two methods produced disparity when the degree of correction was increased. LCHF was mostly related to the remaining bone in the medial closing-wedge DFO.     

Factors affecting stability after medial opening wedge high tibial osteotomy using locking plate: A cadaveric study

ObjectivesTo investigate the effect of screw length, lateral hinge fracture, and gap filling on stability after medial opening wedge high tibial osteotomy (MOW HTO) using a locking plate.MethodsForty tibiae from fresh-frozen cadavers were randomly allocated into five groups. Group A was bicortically fixated, while Group B and Group C were unicortically fixated: 90% and 55% of drilled tunnel length, respectively. Group D was fixated using 90% length screws with a fractured lateral hinge. Group E was fixated using 90% length screws with gap filling using a bone substitute. Operated tibiae were tested under axial compressive load using a material testing machine. The medial gap changes under the serial axial load of 100–600 N and ultimate failure load were measured.ResultsGroup D showed the biggest medial gap change and lowest failure load, while Group E presented the smallest gap change and highest failure load. The medial gap changes tended to increase with shorter screw length, but the difference was not significant between Groups A, B, and C. Group C and Group D showed greater medial gap change and lower failure load compared with Group E, while not differing from Group A and Group B.ConclusionsUnicortical fixation in proximal screw holes of a locking plate was not inferior to bicortical fixation regarding axial stability in MOW HTO, although proximal screws that are too short should be avoided. Lateral hinge fracture decreased, while gap filling with bone substitute increased axial stability.     

Thinner tuberosity osteotomy is more resistant to axial load in medial open-wedge distal tuberosity proximal tibial osteotomy: A biomechanical study

BackgroundThe purpose of this study was to investigate axial load resistance of the tibia depending on the thickness of tibial tuberosity osteotomy in medial open-wedge distal tuberosity proximal tibial osteotomy (OWDTO). The hypothesis is that a thin tibial tuberosity osteotomy shows high axial load resistance of the tibia.MethodsThe OWDTO model was constructed from imitation bones of the tibia. Distal tibial tuberosity osteotomy was performed with thicknesses of 7, 14, and 21 mm (n = 5 for each group). Cyclic axial-load fatigue tests were performed to investigate the strain at five measurement points on the OWDTO model. An axial-load failure test was also performed to investigate the maximum strain for failure.ResultsThe 7-mm OWDTO model showed a significantly lower stain range than the 14-mm model at the middle part of the lateral hinge (P = 0.0263, mean difference: −852.6 με), posterior part (P = 0.0465, mean difference: −1040.0 με), posterior tibial cortex (P < 0.0001, mean difference: −583.4 με), and plate (P = 0.0029, mean difference: −121.6 με). There were no significant differences in the strain at the tibial tuberosity between the groups. The axial load for complete failure was significantly higher in the 7-mm model than in the 21-mm model (P = 0.0010, mean difference: 2577.0 N). The failure points were at the lateral hinges.ConclusionsThinner distal tibial tuberosity osteotomy is more resistant to axial load and may be recommended for the prevention of tibial and lateral hinge fractures after OWDTO.     

Faster bone union progression and less sclerosis at the osteotomy margin after medial opening-wedge high tibial osteotomy using highly porous β-tricalcium phosphate granules versus allogeneic bone chips: A matched case–control study

BackgroundThis study compared bone union progression using highly porous (80% porosity) β-tricalcium phosphate (β-TCP) granules or allogeneic bone chips in the gap created by medial opening-wedge high tibial osteotomy (MOWHTO).MethodsThe study population consisted of 54 patients who received MOWHTO with locking plate fixation: 27 patients using highly porous β-TCP granules, and 27 age- and sex-matched patients using allogeneic bone chips. Bone union progression was evaluated 1, 3, 6, and 12 months postoperatively. The presence of radiographic sclerosis at the osteotomy margin was also assessed.ResultsAmong all patients, the highest degree of bone union observed 12 months postoperatively was grade 4. As postoperative time passed, bone union progression of highly porous β-TCP granules increased linearly and was statistically significant compared with that of cancellous allogeneic bone chips (P = 0.014). The presence of radiographic sclerosis at the osteotomy margin was significantly less common in the β-TCP group than in the allograft group (P = 0.003) and was the strongest predictor of delayed progress of bone union (odds ratio = 6.16, P = 0.006).ConclusionsPatients who underwent MOWHTO using highly porous β-TCP granules had faster new bone remodeling, less radiographic sclerosis at the osteotomy margin, and no inferior clinical outcome compared with allogeneic bone chips, as determined at the 1-year follow up. The presence of radiographic sclerosis at the osteotomy margin in patients undergoing MOWHTO using allogeneic bone or synthetic bone substitute may indicate delayed progress of bone union.     

In vitro stability of open wedge high tibial osteotomy with synthetic bone graft

It has been predicted that significant stress will be applied to the plate and lateral cortical hinge of an osteotomy site when early full weight bearing is commenced after an open wedge high tibial osteotomy. We hypothesized that the stress concentration on the plate or at the lateral cortical hinge would be reduced by inserting bone substitutes into the osteotomy gap. Two different types of tibia model were investigated: Group A, fixation with TomoFix with the osteotomy site left as an open space; and Group B, two β-TCP wedges are inserted into osteotomy site and fixed with TomoFix. Stress at five points was measured using strain gauges. Specimens were mounted onto a testing machine with an FTA (femoro-tibial angle) of 170°. Cyclic load tests and an ultimate load test were then performed. The mean stress on the plate was measured at 15.5 ± 1.8 Mpa in Group A. On the other hand, this value in Group B was only 9.52 ± 2.1 Mpa and this was a significant difference (P < 0.01). The mean stress on the lateral hinge in Groups A and B was 3.31 ± 0.5 and 2.49 ± 0.2, respectively which was also a significant difference (P < 0.05). The mean maximum breaking load in Group A was 2500 ± 280 N and in Group B 4270 ± 420 N which was a significant difference (P < 0.01). Hence, for OWHTO procedures, the use of β-TCP wedges and TomoFix is thus likely to improve the initial axial and possibly rotational stability at the osteotomy site in comparison with methods that leave the osteotomy gap open.     

Mid-term CT assessment of bone healing after nanohydroxyapatite augmentation in open-wedge high tibial osteotomy

BackgroundThe aim of the present study was to confirm the effectiveness of adding nanohydroxyapatite (NHA) to a heterologous bone graft in open-wedge high tibial osteotomy (OWHTO) by measuring the bone density via multislice computed tomography (CT) of the tibial osteotomy gap in a mid-term follow-up (five years).MethodsTwenty-six patients undergoing OWHTO were randomly assigned to two groups: a pure graft group (Group A), in which the osteotomy gap was filled with only heterologous bone graft, and an NHA group (Group B), in which the osteotomy gap was filled with heterologous bone graft and NHA. CT was performed within one week of the operation, after two months, after 12 months and after five years. CT volume acquired in Hounsfield units (HU) was measured on three planes.ResultsThe normal bone density was 110.2 ± 11.7 HU. The value of mean density at five years in Group A was 296.8 ± 81.8 HU, while in Group B, it was 202.2 ± 45.1 HU, showing a density more similar to normal bone and greater bone uniformity inside the osteotomy. The difference between the two groups was statistically significant (p < 0.05). Furthermore, both groups showed excellent mid-term clinical outcomes without significant differences.ConclusionsThis study revealed that absorbability and bone formation at the osteotomy site in the NHA group was significantly higher as compared with the pure graft group at five years postoperatively.     

Early complications of medial opening wedge high tibial osteotomy using autologous tricortical iliac bone graft and T-plate fixation

Despite several advantages of medial opening wedge high tibial osteotomy, this procedure has been noted to have a high rate of complications especially with the use of a spacer plate for fixation. We retrospectively evaluated the early complications of 138 medial opening wedge high tibial osteotomies done using autologous tricortical iliac bone graft and T-plate fixation(AO locking compression T-plate, Ti/3H 4.5-5.0 mm, Synthes, Switzerland, Model No. 440.131 in 30 and low-profile locking T-plate and low-profile locking T-plate in 128 patients.At a mean follow-up of 36.8 months (13 to 78), 26 knees (18.8%) developed complications. Complications varied from osteotomy site infection, loss of correction, broken screws and lateral tibial plateau fracture to joint fluid leakage, pseudoaneurysm and iliac bone fractures. Using the “safe zone” technique and penetrating the lateral cortex with Steinmann pins may help to avoid complications such as loss of correction and lateral tibial plateau fractures.The results of this study indicate that medial opening wedge high tibial osteotomy using autologous tricortical iliac bone graft and T-plate fixation may be a technically demanding procedure associated with a moderate rate of complications. However, these complications could be minimized with proper planning, adequate intra-operative precautions and few modifications to avoid technical error.     

Combined proximal tibial osteotomy for varus osteoarthritis of the knee: Biomechanical tests and finite-element analyses

BackgroundA special combined proximal tibial osteotomy (CPTO) was designed to correct varus osteoarthritis of the knee with severe intra-articular pathologies, which could not be fully corrected by opening-wedge high tibial osteotomy (OWHTO). The biomechanical strength of the CPTO bone–implant construct was evaluated and compared with those of existing osteotomy methods.MethodsThree variations of osteotomy including OWHTO, tibial condylar valgus osteotomy (TCVO), and CPTO were performed on synthetic bones with locking plate and screws. Wedge stiffness, wedge displacement, and load failure were measured by biomechanical tests. Three types of numerical tibial models were also constructed by three-dimensional model reconstruction software. The stability parameters of the three variations including wedge stiffness, wedge displacement, and stress distribution were further measured by finite-element analyses.ResultsThe biomechanical testing results revealed that the wedge stiffness, wedge displacement, and failure load of the CPTO construct were very close to those of the OWHTO construct. The numerical results of wedge stiffness and displacement showed good conformity to the previous biomechanical results. The stress distribution at the lateral hinge, the plate corner, and the holes of the CPTO construct were close to those of the OWHTO counterpart, while the stress distribution at the inter-condylar eminence of the tibia and at the middle region of the screws was close to those of the TCVO counterpart.ConclusionsThe CPTO construct can provide comparable strength for early mobilization and rehabilitation to that of the OWHTO construct.     

Opening wedge distal femoral varus osteotomy for lateral compartment osteoarthritis in the valgus knee

IntroductionOsteotomy aims to reduce pain and the rate of progression of arthritis by correcting deformity and offloading the affected compartment. This study reports the results of a case series of opening wedge distal femoral varus osteotomies for valgus lateral osteoarthritis of the knee.Patients and methodsEighteen patients underwent osteotomy surgery (21 knees) with the aim of correcting the mechanical axis to 48–50% from medial to lateral.ResultsThe mean follow-up for the study population was 4.5 years (range 1.6 to 9.2 years). Four patients underwent conversion to arthroplasty at a mean time of 3.3 years postosteotomy. Kaplan–Meier analysis demonstrates a cumulative survival of 79% at 5 years. In the remaining 17 osteotomies, all patients reported that outcome measures improved from baseline. However, only the IKDC and pain subdomain of KOOS showed a statistically significant and clinically relevant difference. Re-operation for non-arthroplasty related surgery was common. In part this was due to symptoms related to prominence of metalwork (10). Other reasons included non-union (1), loss of correction (2), infection (1), and persistent symptoms (2).ConclusionCumulative survival of opening wedge DFVO is comparable with that reported in closing wedge series. Clinically relevant differences in the IKDC and KOOS pain scores suggest that opening wedge DFVO is a useful option in the management of valgus gonarthrosis. However, DFVO is a technically demanding procedure and re-operation, particularly for removal of metalwork, is common.     

Medial meniscus extrusion and stage are related to the size of spontaneous osteonecrosis of the knee in patients who underwent high tibial osteotomy

PurposeSpontaneous osteonecrosis of the knee (SONK) causes acute atraumatic knee pain, and meniscus tears may be associated with the pathogenesis of SONK. The purpose of this study was to investigate the relationship of the type of meniscus tear and medial meniscus extrusion with SONK on the medial femoral condyle in patients who underwent surgical treatment with high tibial osteotomy due to severe knee pain.MethodsWe enrolled 98 patients with 102 knees who underwent medial opening wedge high tibial osteotomy (OWHTO) under the diagnosis of medial femoral condyle osteonecrosis at our hospital from December 2003 to January 2020. Based on the Koshino classification, cases of SONK were classified as stage 1–4. The relationships of demographic data, X-rays and MRI images, including femorotibial angle (FTA), meniscus tear type, and medial meniscus extrusion (MME), with the stage and volume of SONK were investigated.ResultsNinety-eight patients (29 males and 69 females), with an average age at surgery of 69.2 ± 9.6 years and Body mass index(BMI) of 61.0 ± 17.6 kg/m². In 102 cases of SONK, 11 knees, 18 knees, 46 knees, and 27 knees were classified as stage 1–4, respectively. The mean SONK volume was 2161.61 µm (range 95.67–7484.68 µm) on preoperative MRI. The preoperative FTA (mean 180.86°, range 172–187°) was not associated with the stage or volume of SONK. Meniscus tears were found in all cases of SONK and consisted of 2 degenerations, 2 horizontal tears, 0 vertical tears, 40 radial tears, 4 complex tears, and 54 medial meniscus posterior root tears (MMPRTs). In addition, 99% (101/102) of knees showed more than 3 mm of meniscus extrusion. Although the meniscus tear type was not associated with SONK stage, there was a high rate of tears that caused disruption of the hoop strain, such as MMPRTs (52.9%) or radial tears (39.2%). MME was significantly related to SONK volume (r = 0.387, p < 0.001).ConclusionAll patients with SONK had coexisting meniscus tears, most menisci had medial extrusion, and a positive correlation was observed between MME and SONK volume.     

Midterm follow-up results of two different types of implants in opening wedge high tibia osteotomy

BackgroundThis retrospective study investigated the midterm results of medial opening wedge high tibia osteotomy, with a monoplanar or a biplanar osteotomy using two types of implant system.MethodsOsteotomies were performed on 241 knees (231 patients). The mean follow-up period was 6.0 years (SD 3.0, range 0.2–12.8 years). Two types of implant system were used, a precountered non-locking plate (PP) (n = 74) and a precountered locking plate (LP) (n = 167). A Kaplan-Meier cumulative survival curve and a Cox regression model were used to analyse and revise survival and risk factors.ResultsCumulative survival estimates for LP were 80% at 5 years, and 64% at 10 years (SE = 0.4, CI 95%: 9.0–10.5), and for PP, they were 68% at 5 years and 49% at 10 years (SE = 0.5, CI: 95% 6.3–8.2) (p = 0.024). The revision rate was 26% (44/167) for the LP group, and 47% (35/74) for the PP group (p = 0.001). Reoperations on LP osteotomies occurred for the tibial monoplanar cut and biplanar cut groups, in 19/52 (37%) and 25/167 (16%) osteotomies, respectively (p = 0.04). Our Cox regression model showed that PP had a higher risks (RR = 1.7; CI: 95% 1.1–2.6) of revision, when compared with LP (p = 0.026).ConclusionsThe risk of revision for any reason and that of early conversion to total knee arthroplasty (TKA) after high tibia osteotomy were significantly increased for PP, when compared with LP.     

High protracted 99mTc-HDP uptake in synthetic bone implants — A potentially misleading incidental finding on bone scintigraphy

We report the case of a 56-year-old male with bilateral total knee prostheses suffering from bilateral knee pain mainly on the right side and referred for bone scintigraphy. The medical history of the patient revealed an opening wedge high tibial osteotomy performed nine years earlier, with insertion of two blocks of ceramic made of hydroxyapatite and tricalcium phosphate in a wedge configuration as synthetic bone substitutes. The porous structure of these implants is analogous to the architecture of cancellous bone and permits fibrovascular and bone ingrowth, promoting the healing process. Planar scintigraphy and SPECT/CT showed an intense uptake within those implants in the early phase as well as in the late phase of the bone scan. It also showed bilateral patellofemoral arthritis. A ^99mTc-labeled antigranulocyte antibody scintigraphy was negative for infection or inflammation. Bilateral patellar resurfacing led to complete symptom regression, confirmed at 10 months follow-up. To the best of our knowledge, this scintigraphic pattern with such a high tracer uptake reflecting bone substitute osteointegration has not yet been published. This should be considered in patients with such bone replacement materials that are increasingly used, in order to avoid false diagnosis of inflammation or infection.     

The efficacy of porous hydroxyapatite chips as gap filling in open-wedge high tibial osteotomy in terms of clinical,radiological, and histological criteria

PurposeHydroxyapatite (HA) does not fully degrade, which raises concerns about poor remodeling and incorporation into the bone after open-wedge high tibial osteotomy (HTO). The purpose of this study was to compare the results between gap filling with allogenous chip bone and HA chip after open-wedge HTO using propensity score matching and to analyze the radiological unabsorbed area of opening gaps histologically in HA using patients.MethodsThe matched variables were age, body mass index, sex, correction angle, and smoking status. After matching, the allogenous group and HA group included 33 patients each with two years of follow-up. The range of motion (ROM), International Knee Documentation Committee (IKDC) subjective score, Knee Injury and Osteoarthritis Outcome Score (KOOS), mechanical axis (MA), tibial slope, osteoconductivity, and absorbability were evaluated and compared between both groups. Among the HA group, 20 patients underwent bone biopsy and histologically analyzed of the radiological unabsorbed area.ResultsThe postoperative ROM, IKDC subjective score, and KOOS were similar in both groups. The osteoconductivities did not differ significantly. The absorbability in the HA group was significantly lower than allogenous group (59.6% vs. 22.6%, P < .001). The histological sections of the radiological unabsorbed area showed mature lamelliform bone tissues were significantly greater than structurally degraded remnant HA (30.4% and 4.2%, P < .001).ConclusionThe HA chips showed an inferior absorbability, however, a mature lamelliform bone was observed in significantly larger amounts than remnant HA in the radiological unabsorbed area. The allogenous bone chips and HA chips showed similar clinical and radiological results after open-wedge HTO.     

Analysis of the tumor necrosis factor superfamily member 11 gene polymorphism with bone mineral density and bone fracture frequency in patients with postmenopausal osteoporosis

PurposeWe aimed to examine the polymorphism of the promoter and exon 5 of the TNFSF11 gene and their impact on bone mineral density (BMD) and the frequency of bone fractures. TNFSF11 encodes the receptor activator of the NF-kB ligand (RANKL), a key regulator of bone metabolism and osteoporosis drug targets. BMD is an essential measure in diagnosing osteoporosis and assessing the risk of fractures. In vivo, RANKL expression research suggests that promoter TNFSF11 variants influence BMD. Moreover, exon 5 polymorphism of a linear epitope sequence for a denosumab could be related to the effectiveness of biological therapy.Patients and methodsThe study included 114 postmenopausal osteoporosis patients. BMD was measured in the lumbar spine and the femoral neck. Genetic analysis was performed using Sanger sequencing. Genotypes data for 263 female European population group were obtained from the 1000Genomes database.ResultsWe identified six promoter polymorphisms (rs9525641, rs9533155, rs9533156, rs11839112, rs28926171, rs183599708) and one silent TNFSF11 variant in exon 5 (rs9562415). Three of the sequence variants detected (rs9525641, rs9533155, rs9533156) proved to be polymorphic, whereas the others four occurred at a frequency below 2%. The statistical analysis demonstrated no significant differences between polymorphisms and BMD, and bone fractures. However, variant rs9533156 was relevant with the lumbar spine T-score (p = 0.0273), and no association with BMD was of borderline significance (p = 0.0529).ConclusionsVariant rs9533156 may contribute to the genetic regulation of BMD in Polish postmenopausal osteoporosis, while the exon 5 sequence of the TNFSF11 gene is very conservative.     

A preference-based single-item measure of quality of life following medial opening wedge high tibial osteotomy: Large improvements similar to arthroplasty

BackgroundImprovements in generic and disease specific scores have been reported with medial opening wedge high tibial osteotomy (MOW HTO). However, meaningful comparisons between competing surgical interventions have been hampered by the lack of a preference based single index of health related quality of life (HRQoL). The primary aim of this study was to derive and report a single index measure of HRQoL for patients undergoing MOW HTO, preoperatively and at 12 and 24  postoperatively. Secondary aims were to evaluate changes in various additional measures of quality of life at these time points.MethodsThe impact of MOW HTO was evaluated using generic and disease specific instruments. One hundred thirty eight patients completed the Medical Outcomes Study short form health survey (SF-12) and Knee Osteoarthritis Outcomes Score (KOOS) before, 12 and 24 months after surgery. A preference-based single index measure of HRQoL was calculated and changes were evaluated.ResultsThe mean change in the HRQoL suggested large, clinically significant improvements from 0.69 preoperatively to 0.82 (p < 0.001) and 0.8 at 12 and 24 months postoperatively respectively. All dimensions of the SF-12, except role mental health, and all dimensions of the KOOS also demonstrated statistically significant improvements between pre and postoperative measurements.ConclusionsThe preoperative HRQoL of young patients with mechanical varus alignment and medial compartment knee osteoarthritis is similar to older patients with knee osteoarthritis. Medial opening wedge high tibial osteomoty results in significant improvements in HRQoL, the magnitude of which is comparable to other surgical interventions for knee osteoarthristis.     

The risk factors for mechanical complication in endoprosthetic reconstruction of knee osteosarcoma

BackgroundThe increased limb survival rates and higher functional demands have also increased the mechanical complication rates of megaprostheses. This study aimed to analyse possible risk factors which can predispose patients to mechanical complications.MethodsPatients with knee osteosarcoma referred to our clinic from 1992 to 2014 were investigated retrospectively. The patients who underwent surgical resection and endoprosthetic reconstruction with at least 5 years of follow up were analysed. The revision of the megaprosthesis due to a mechanical complication was accepted as an endpoint. The possible risk factors, including cement usage, implant material, joint mechanism, neoadjuvant radiotherapy, and anatomical localization of the lesion, were analysed for any association with mechanical complication rates.ResultsA total of 118 patients were included for final analysis. The average age was 24.5 years (standard deviation ±10.1, range: 15–64). Mechanical complication rate was 22% which included 19 aseptic loosenings and seven implant failures. The average time to mechanical complication was 32.5 months. Overall, 5-year implant survival was 78%. Multiple regression analysis revealed that cement usage is an independent risk factor for mechanical complication (P = 0.007). Although the 5-year implant survival was higher in rotating hinge and titanium implants compared with fixed hinge and cobalt chrome, the multiple regression model did not yield a correlation with mechanical complication rates.ConclusionCemented implants showed significantly higher mechanical complication rates compared with cementless ones in this series of knee osteosarcoma patients who underwent megaprosthetic reconstruction. Hinge mechanism and implant material did not have a significant effect on mechanical complication rates.     

Osteoporotic Fractures of the Spine,Hip, and Other Locations after Adjuvant Endocrine Therapy with Aromatase Inhibitors in Breast Cancer Patients: a Meta-analysis

BackgroundAromatase inhibitors (AIs) play an important role in the endocrine therapy of postmenopausal breast cancer patients, with a recent tendency to extend the duration of their use. However, AIs may increase the risk of osteoporotic bone fractures. This meta-analysis evaluated the risk of osteoporotic fractures of the hip, spine, and other locations in breast cancer patients using AIs.MethodsWe performed a systematic search to identify randomized controlled clinical trials that investigated osteoporotic fractures in breast cancer patients on AI therapy. The main outcomes were the incidence and risk of osteoporotic fractures in general and of hip, vertebral, and non-vertebral fractures in AI users and controls.ResultsThe systematic review found a total of 30 randomized controlled trials including 117,974 participants. The meta-analysis showed a higher incidence of osteoporotic fracture in AI users: The crude risk ratio for all osteoporotic fractures was 1.35 (95% confidence interval [CI], 1.29–1.42; P < 0.001), for hip fractures 1.18 (95% CI, 1.02–1.35; P < 0.001), for vertebral fractures 1.84 (95% CI, 1.36–2.49; P < 0.001), and for non-vertebral fractures 1.18 (95% CI, 1.02–1.35; P < 0.001), respectively, compared to the controls.ConclusionOur meta-analysis suggested an increased risk of osteoporotic fractures for AI therapy in patients with breast cancer that was most expressed for vertebral fractures. Breast cancer patients on AIs need to be monitored for osteoporosis and osteoporotic fractures, and active prevention measures should be implemented.