Femorotibial angle on short knee radiographs fails to accurately predict the lower limb mechanical alignment. A systematic review and meta-analysis on different femorotibial angle definitions and short knee radiograph types.

Introduction: Hip-knee-ankle angle (HKA) on Full Limb Radiographs (FLRs) is the gold standard for coronal knee alignment assessment. Despite the widespread utilization of the more convenient femorotibial angle (FTA) on either antero-posterior (AP) or postero-anterior (PA) short knee radiographs (SKRs), its definition and correlation with HKA remains controversial. This review is the first to systematically investigate FTA-HKA correlation and the effect of different FTA methods and SKRs. Methods: Systematic literature search (Pubmed, Scopus, Cochrane Library) followed PRISMA guidelines, to evaluate studies examining the FTA-HKA correlation. Meta-analyses compared the 3 most common FTA methods, knee center determination method and SKR types. Results: 17 studies (2597 patients, 3234 knees) were included. The strongest correlation with HKA (r = 0.78) was found for FTA Method 1 (angle formed by lines drawn from the midpoint of tibial spines to points 10 cm above and below the joint line). No significant differences were observed when grouping the FTA methods by knee center assessment (Group I, r = 0.78; Group II, r = 0.77). AP SKRs showed a trend towards stronger FTA-HKA correlation compared to PA SKRs, in both Method 1 (r = 0.79 vs 0.75) and Method 3 (r = 0.80 vs 0.66). Conclusion: Irrespective of its definition or type of SKR used, FTA lacks reliable accuracy in predicting the HKA in most knees. FLRs should be used whenever precise estimation of the patient's alignment is necessary. Caution is warranted in interpreting studies investigating knee alignment or knee arthroplasty outcomes based on FTA.

Static Baropodometry for Assessing Short-Term Functional Outcome after Unilateral Total Knee Arthroplasty: Exploring Correlation between Static Plantar Pressure Measurements and Self-Reported Outcomes.

This study aimed to investigate the association between objective baropodometric and radiological measurements and patient self-reported functional outcomes, assessed through the Knee Injury and Osteoarthritis Outcome Score (KOOS). Additionally, it sought to evaluate the effectiveness of static baropodometry in predicting short-term KOOS results following unilateral total knee arthroplasty (TKA). We conducted a prospective single-center study involving 32 patients who underwent unilateral TKA for knee osteoarthritis (KOA). Patients were evaluated both preoperatively and six months postoperatively, utilizing objective measurements derived from static baropodometric analysis in a normal, relaxed, bipedal standing position using a multi-platform Plantar Pressure Analysis System (PPAS) and radiographic measurements of the femorotibial angle (FTA) and subjective assessments through the national validated version of the KOOS. The study found an insignificant average correction of -0.69° ± 4.12° in the preoperative FTA at the sixth month after TKA. Moreover, there were no significant differences in the KOOS based on different types of knee alignment (KA) both pre- and postoperatively (p > 0.05). No significant correlations were observed between the KOOS, and total average affected and unaffected plantar pressures (TAAPP and TAUPP) pre- and postoperatively, as well as KA pre- and postoperatively. However, significant changes were observed in TAAPP and TAUPP measurements after unilateral TKA. TAAPP demonstrated a significant increase postoperatively (mean change (SD) = 18.60 (47.71); p = 0.035). In conclusion, this study found no significant correlation between KA, static baropodometric measurements, including pre- and postoperative differences, and KOOS outcomes. Therefore, static plantar pressure measurements alone might not serve as a reliable predictor of short-term clinical outcomes after unilateral TKA, as reported by patients.

Validating Knee Varus Alignment Measurements Using Markerless Motion Capture.

This study aimed to determine the validity of specific knee varus alignment measurement methods. We measured the femorotibial angle (FTA) using radiography and optical motion capture and validated the FTA measurement using markerless motion capture. The subjects included 34 legs of 19 patients with knee osteoarthritis (OA). One-way analysis of variance and multiple comparison tests were used to compare the FTA values between the Kellgren-Lawrence classification (KL) and Pearson's correlation coefficient for validity. The analysis showed that the FTA measured by markerless motion capture had a significant correlation to the FTA measured by radiography (r = 0.869, p < 0.01) and significantly increased with increasing KL (p < 0.05). These results indicate that markerless motion capture is a valid outcome measure for varus alignment in patients with knee OA.

Comparison of postoperative alignment using fixed angle versus variable angle distal femoral resection in uncomplicated total knee replacement.

PURPOSE: This study aimed to compare the postoperative alignment of the lower limbs using fixed angle versus variable valgus angle distal femur resection in uncomplicated total knee replacement (TKR) and to determine the mean valgus correction angle (VCA) in the study population. METHODS: This was a prospective comparative study conducted between July 2018 and December 2019 in patients with osteoarthritic knees who underwent primary TKR. Forty-nine patients with 54 knees completed the study. They were randomized into fixed valgus angle (group A) and variable valgus angle (group B) groups. Twenty-four patients with 26 knees were in group A who had distal femur resection with 5-degree valgus correction, while 25 patients with 28 knees were in group B who had distal femur resection with individualized valgus correction angle calculated from hip-knee-ankle scanogram. RESULTS: The demographic data were comparable in the two groups. There was no statistically significant difference between the groups in the mean preoperative mechanical femorotibial angle (MFTA). The fixed angle group had a mean postoperative MFTA of 2.0 ± 2.8°, while variable angle group had a mean of 1.6 ± 2.4°. However, the difference between the groups did not reach statistical significance (p = 0.60). The mean VCA in the study population was 5.8 ± 1.2° (Range 4-9°). CONCLUSION: Our study has shown that the use of variable valgus angle for distal femur resection in uncomplicated TKR did not significantly improve the accuracy of restoring the postoperative coronal alignment within 0 ± 3°.

The relationship between the ''Fujisawa point'' and anatomical femorotibial angle following simulated open wedge high tibial osteotomy.

BACKGROUND: We evaluated the relationship between the weight-bearing line (WBL) ratio and anatomical femorotibial angle (FTA) by simulated open wedge high tibial osteotomy (OWHTO). This study evaluated the correlation between the ''Fujisawa point'' and FTA, and identified factors which caused deviations between the two measurement methods. We hypothesized that the Fujisawa point corresponded with 170° of the FTA. METHODS: Preoperative antero-posterior full-length lower limb radiographs of 82 patients were obtained for the OWHTO to place the WBL ratio at a target of 62.5% of the width of the tibial plateau (Fujisawa point). The coronal alignment was measured pre- and post-planning. The patients were divided into two groups by the post-planning FTA: a correspondence group (168.5°â‰¦FTA≦171.5°) and a non-correspondence group (FTA < 168.5°, 171.5° < FTA). The relationship between the Fujisawa point and the FTA was analyzed with multivariate regression analysis. RESULTS: The post-planning FTA was 169.8 ± 1.1° and within 170 ± 1.5° in 69 cases (84.1%) when the WBL ratio was 62.5%. The neck shaft angle was 128.1 ± 5.2° in the correspondence group, and 122.3 ± 6.3° in the non-correspondence group. The multivariate linear regression analysis revealed that the neck shaft angle was the only factor that predicted the correspondence of the Fujisawa point with the FTA at 170° (p = 0.006, odd 1.28). CONCLUSIONS: The post-planning FTA converged at 170° when the WBL ratio passed through the Fujisawa point and the neck shaft angle was the only predictor.

Using short knee radiographs to predict the coronal alignment after TKA: Is it an accurate proxy for HKA on full-length images?

BACKGROUND: The postoperative clinical outcomes has been extensively demonstrated to correlate with the coronal alignment after total knee arthroplasty (TKA). However, in different studies, either the hip-knee-ankle angle (HKA) on a full-length radiograph or the femorotibial angle (FTA) on a short knee film was used to categorize the postoperative coronal alignment. Meanwhile, several different FTA ranges were regarded as neutral alignment in different studies. As a result, it is still unknown that how FTA on short knee films and HKA related to each other. The FTA may be able to become an accurate proxy of HKA to predict the coronal alignment. The purpose of this study was to explore the correlation between the FTA and the HKA after TKA and to find the most accurate FTA range. METHODS: About 223 patients were included in this study and standard weight-bearing short knee films as well as full-length radiographs were acquired. The pre- and postoperative FTA, as well as the postoperative anatomical lateral distal femoral angle (aLDFA) and anatomical medial proximal tibial angle (aMPTA) were measured on short knee films by two orthopedic surgeons independently. On full-length films, the pre- and postoperative FTA, the pre- and postoperative HKA, as well as the postoperative mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibial angle (mMPTA) were also recorded by two other surgeons independently. Pearson correlation analysis was performed to compare FTA and HKA, aMTPA and mMTPA, aLDFA and mLDFA, respectively. RESULTS: The postoperative FTA and HKA had a good correlation (r = 0.86). The agreements were reached 82.7%, 71.0%, and 68.2% of all patients using three previously reported FTA ranges. When analyzing the independent alignment of the tibial tray and the femoral component, 84.1% and 57.9% of all patients was reached an agreement on the classification. CONCLUSIONS: On most occasions, the consistence between the FTA and HKA in assessing the coronal limb alignment of the lower extremity and the tibial component is satisfactory. However, the postoperative full-length film is still needed to evaluate accurately the coronal alignment of the femoral component.

Non-weight-bearing short knee radiographs to evaluate coronal alignment before total knee arthroplasty.

BACKGROUND: Whole leg radiograph (WLR) is the gold standard in assessing lower limb alignment before total knee arthroplasty (TKA) although in practice, non-weight-bearing short knee radiographs (NWB SKRs) are used by most medical institutions. The objective of this study was to determine whether the femorotibial angle (FTA) could be used to evaluate lower limb alignment on limited NWB SKRs. We also investigated whether FTA alignment measurements on NWB SKRs and WLRs differed depending on the direction of knee deformity. METHODS: In all, 105 knees which underwent both NWB SKR and WLR were included. Measurement of hip-knee-ankle angle (HKA) was obtained through WLR, while the FTA was found using NWB SKR (FTASKR) and WLR (FTAWLR). All knees were divided into three groups based on the HKA. The Kappa statistic was used to compare the agreement of categorical alignment variables between the HKA and FTASKR. The agreement of the measurements obtained from the two radiographs was made using Bland-Altman plots and intraclass correlation coefficient (ICC). Pearson correlation coefficient and simple linear regression analysis were also conducted to evaluate the correlation between different angles. RESULTS: The agreement for categories of lower limb deformity was rated excellent (kappa =0.804, P<0.001). The Bland-Altman plot showed that the mean difference for the FTASKR and FTAWLR was 4.4°. There was an excellent correlation (r=0.861, P<0.001) and good reliability (ICC, 0.607) between the FTASKR and HKA. For the varus group, there was a good correlation between the FTASKR and HKA (r=0.650, P<0.001); however, there were no significant correlations between the FTAS KR and HKA in the neutral (r=0.106, P=0.543) and valgus groups (r=0.322, P=0.102). CONCLUSIONS: For outpatient follow-up, we found that the FTA on NWB SKRs is an acceptable means for classifying knee alignment (varus, neutral, or valgus). The measurement on NWB SKR also showed excellent correlation and good agreement with the HKA. For varus knees, NWB SKR measurements showed the best correlation with the HKA. However, for neutral and valgus knees, NWB SKR measurements were insufficient for conducting a reliable calculation and quantification of coronal alignment of the lower limb.

Factors associated with dynamic knee valgus angle during single-leg forward landing in patients after anterior cruciate ligament reconstruction.

BACKGROUND: A few studies have reported on how to predict increased dynamic knee valgus angle (KVA), a risk factor for second anterior cruciate ligament (ACL) injury after ACL reconstruction. This study aimed to identify the factors with the potential to predict the KVA during single-leg hop landing. METHODS: Using three-dimensional motion analysis systems, knee motion during a single-leg hop landing task was measured in 22 patients who had undergone ACL reconstruction at 8-10 months postoperatively. The KVA at initial contact (IC) and maximum KVA during the 40-ms period after IC were calculated using the point cluster technique; correlations between the KVA and other factors were assessed. We performed multiple regression analysis to determine whether KVA could be predicted by these parameters. RESULTS: The KVA was significantly negatively correlated with the static femorotibial angle (FTA; P < 0.01) and patient height (P < 0.01). It was positively correlated with the body mass index (P < 0.05). Multiple regression analysis showed that a small FTA could predict the KVA at IC (ß: 0.52, 95% confidence interval (CI): 2.24-(-0.42); P < 0.01). The maximum KVA during the 40-ms period after IC was associated with the FTA (ß: 0.46, 95% CI: 2.22-(-0.26); P = 0.02) and height (ß: 0.40, 95% CI: 0.59-(-0.02); P = 0.04). CONCLUSION: At 8-10 months after ACL reconstruction, the KVA was significantly correlated with the FTA, with reduced FTA being associated with an increased dynamic KVA during single-leg hop landing. The measurement of anatomical parameters may aid in predicting the second ACL injury risk after reconstruction.

Comparison of 3d printing assisted osteotomy of distal femur and osteotomy of distal femur in the treatment of genu valgus osteoarthritis / 中国组织工程研究

BACKGROUND: Closed osteotomy of distal femur has a good effect in the treatment of genu valgus osteoarthritis, but the angle of osteotomy cannot be measured directly during the operation. It is necessary to correct the force line through repeated fluoroscopy and adjustment of osteotomy amount. Improper operation may cause iatrogenic rotation deformity. OBJECTIVE: To compare the effect of 3D printing assisted osteotomy of distal femur with conventional osteotomy of distal femur in the treatment of knee osteoarthritis. METHODS: From January 2014 to February 2018, 28 patients (37 knees in total) with osteoarthritis caused by genu valgus aged 28-60 years were enrolled from the First Hospital of Putian City. All patients were randomly divided into two groups. Patients in the control group (11 cases, 16 knees) were treated with conventional closed osteotomy of distal femur combined with locking compression plate implantation. Patients in the experimental group (17 cases, 21 knees) were treated with 3D printing module assisted with closed osteotomy of distal femur combined with locking compression plate. The operation time and times of fluoroscopy were recorded. The KOOS score, femorotibial angle, lateral angle of distal femur and fracture healing time were compared between the two groups before and after treatment. The experiment was approved by the Ethics Committee of the First Hospital of Putian City. RESULTS AND CONCLUSION: (1) Operation time and the times of fluoroscopy in the experimental group were less than those in the control group (P 0.05). (3) Femorotibial angle and lateral angle of distal femur in both groups were larger than those before operation (P 0.05). (4) There was no significant difference in the healing time between the two groups (P > 0.05). (5) The results showed that closed osteotomy of the distal femur can achieve good results in the treatment of genu valgus osteoarthritis. 3D printing technology can simplify the osteotomy operation, reduce the operation time, and the times of fluoroscopy.

Association between medial meniscus extrusion and spontaneous osteonecrosis of the knee.

AIM: Medial meniscus tear has been proposed as a potential etiology of spontaneous osteonecrosis of the knee (SONK). Disruption of collagen fibers within the meniscus causes meniscal extrusion, which results in alteration in load distribution in the knee. Our purpose was to determine whether the extent of medial meniscus extrusion correlates with the severity of SONK in the medial femoral condyle. METHODS: Radiological stage of SONK and femorotibial angle (FTA) were determined on knee radiographs. Ellipsoid volume of SONK lesion and meniscal pathology (degeneration, tear and extrusion) were evaluated by magnetic resonance imaging. RESULTS: All the 18 knees with SONK in the present study showed substantial extrusion (≥ 3 mm) and degeneration of the medial meniscus. The extent of meniscal extrusion and FTA were strongly associated with the stage and volume of the SONK lesion. Multiple linear regression analysis revealed that medial meniscus extrusion and FTA were useful predictors of the volume of the SONK lesion. CONCLUSION: There was high association of medial meniscus extrusion and FTA with the radiological stage and volume of the SONK lesion. Increased loading in the medial femoral condyle with greater extrusion of medial meniscus and varus alignment may contribute to expansion and secondary osteoarthritic changes of a SONK lesion.

Evaluation of the relationship between the femoro-tibial angle and meniscal injury.

OBJECTIVE: The purpose of this study was to assess the relationship between the presence of meniscal injury and the femorotibial angle in the knee joint. METHODS: Patients who underwent knee magnetic resonance imaging (MRI) at our department between January 2015 and March 2015 were included in this study. Knee MR images of these patients were retrospectively re-evaluated for meniscal injury. The anatomic femorotibial angle measurements of the patients were calculated using AP knee radiograms. The relationship between femorotibial angle values and the presence of meniscal injury was analyzed. RESULTS: One hundred and fourteen knee joints of 101 patients were included. The mean age of the patients was 40.6±13.4 years. The number of injured medial menisci was 92 and the average femorotibial angle in these knees was 5.6±1.88; the number of non-injured medial menisci was 22 and the average femorotibial angle value in these knees was 5.8±1.92 (p=0.82); The number of lateral meniscus with injury was 22 and the mean femorotibial angle value in these knees was 6.1±1.50; the number of lateral meniscus without injury was 92 and the average femorotibial angle value in these knees was 5.6±1.96 (p=0.20). CONCLUSION: In our study, there was no statistically significant correlation between femorotibial angle values and the presence of injury in medial and lateral meniscuses. We believe that frontal plane bone alignment disorder of the knee does not have a predisposition to meniscal injury.

Postoperative Coronal Alignment After Total Knee Arthroplasty: Does Tailoring the Femoral Valgus Cut Angle Really Matter?

Postoperative alignment was measured in 80 TKA divided into 2 groups. Knees in the tailored group (n=40) were performed with a personalized valgus cut angle (VCA) based on preoperative hip-to-ankle (HTA) radiographs. The fixed group knees (n=40) were performed utilizing a 4° VCA in valgus knees and obese patients, and 5° in neutral and varus knees. There was no significant difference between groups in average preoperative mechanical alignment or average severity of preoperative deformity. There was no statistically significant difference between groups in postoperative mechanical alignment (tailored: 2.6°; fixed: 1.3°; P=0.08) or severity of residual deformity (tailored: 3.5°; fixed: 2.6°; P=0.10). Accuracy of the tibial cut angle (TCA) and severity of the preoperative deformity were strong independent predictors of postoperative alignment (R(2)=58% and R(2)=33%, respectively).

A correlation between osteophytes in knee-joint and lower limb alignment in adult patients with Kaschin-Beck disease / 中华地方病学杂志

Objective To evaluate the correlation between osteophytes size and lower limb alignment in the knees of patients with Kaschin-Beck disease (KBD).Methods A total of 300 clinically diagnosed patients with KBD were X-rayed on knee-joints which ranged from the distal half of femur to proximal half of tibia.Meanwhile some related parameters in the X film with the anteroposterior position (including osteophytes length,femorotibial angle,femorotibial joint space ratio of inner side to outer side) were measured by DICOM 2.0,a software of medical graphic measuring,then followed by calculating the osteophyte spur index.The association between femorotibial angle,femorotibial joint space ratio and osteophytes spur index was evaluated by Pearson correlation test.Results The average of femorotibial angle of all the tested knee-joints was (165.97 ± 4.02)°,which positively correlated with both the osteophyte spur index of the medial femoral condyle [(6.54 ± 3.12)％,correlation coefficient (r) =0.524,P＜0.01] and the osteophyte spur index of medial tibil plateau [(7.14 ± 3.40)％,r =0.578,P ＜0.01].The femorotibial joint space ratio was 0.61 ± 0.13,which positively correlated with both the osteophyte spur index of medial femoral condyle (r =0.531,P ＜0.01) and that of the medial tibil plateau (r =0.563,P ＜0.01).Conclusions The results of this study indicate that there is a positive correlation between lower limb alignment and osteophyte size of both the medial femoral condyle and the medial tibial plateau.This finding may be evidenced by the fact that the changes of lower limb biomechanics may contribute to formation and development of osteophytes in the kneejoint.

The fracture sites of atypical femoral fractures are associated with the weight-bearing lower limb alignment.

PURPOSE: Atypical femoral fractures (AFFs) are stress-related fractures that are speculated to associate with long-term treatment with bisphosphonates for osteoporosis. A history of AFF is a high risk factor for the development of a subsequent AFF in the same location of the contralateral femur, suggesting that a patient's individual anatomical factor(s) are related to the fracture site of AFFs. In this study, we investigated the radiographs of fourteen AFFs (four bilateral fractures among ten patients) treated at six hospitals associated with our university between 2005 and 2010. The fracture site and standing femorotibial angle (FTA), which reflects the mechanical axis of the lower limb, were measured on weight-bearing lower limb radiographs. The fracture site and FTA of patients with typical femoral fractures (TFF) were compared to those of patients with AFFs. The correlations were examined using Spearman's rank correlation coefficients. The fracture locations in the femora were almost the same in the patients with bilateral AFFs. There was a positive correlation between the fracture site and the standing FTA in the patients with AFFs (r=0.82, 95% confidence interval; 0.49 to 0.94), indicating that the larger the standing FTA (varus alignment), the more distal the site of the fracture in the femur. The FTA of the patients with atypical diaphyseal femoral fracture were significantly larger compared to that of those with not only atypical subtrochanteric fractures but also TFFs. In conclusion, the fracture sites of AFFs are associated with the standing lower limb alignment, while those of TFFs are not.

A comparison of variable angle versus fixed angle distal femoral resection in primary total knee arthroplasty.

This study assessed whether using a variable distal valgus resection angle improved post-operative coronal lower limb alignment in total knee arthroplasty (TKA). Two groups were compared: Fixed (n = 124), where a fixed distal valgus resection angle of 7° was used; Variable (n = 87), where the resection angle was adjusted to the measured femoral mechanical anatomical (FMA) angle of the patient. FMA and mechanical femoro-tibial (MFT) angles were measured on pre-operative and post-operative hip-knee-ankle radiographs. 85% of patients in the Variable group had a post-operative MFT angle within 0° ± 3°compared to 69% in the Fixed group (P = 0.006). The use of a fixed distal femoral resection angle for all patients is not appropriate. Setting the resection to an individual patient's FMA angle can significantly improve the post-operative MFT angle.

Treatment of total knee replacement following failed high tibial osteotomy / 军事医学

Objective To investigate the effect of total knee arthroplasty ( TKA) following high tibial osteotomy ( HTO) and to analyze the factors that may influence the operation .Methods A total of 16 patients (19 knees) who had undergone a previous HTO were treated with TKA between 2000 and 2010.The American Knee Society Scores ( KSS), femorotibial angle ,quadriceps angle ,posterior slope angle of tibial plateau ,Insall Salvatti Ratio and knee range of motion ( ROM) were evaluated for each patient pre-and post-operatively and the results were evaluated .Results The KSS scores improved from 73.20 ±3.56 scores preoperatively to 153.00 ±3.39 scores postoperatively (P <0.05).The femorotibial angle was corrected from 160.57°±3.30°preoperatively to 169.85°±1.34°postoperatively(P<0.05).The quadriceps angle was corrected from 24.57°±2.07°preoperatively to 17.28°±1.11°postoperatively (P<0.05).The posterior slope angle of tibial plateau was corrected from 2.25°±0.50°preoperatively to 3.75°±0.95°postoperatively (P<0.05).The Insall Salvatti Ratio improved from 0.80 ±0.08 preoperatively to 1.05 ±0.12 postoperatively ( P <0.05).The knee ROM improved to 38.25°±8.88°postoperatively from 96.25°±4.34°preoperatively(P<0.05).Conclusion TKA following HTO demands adequate soft tissue balancing , good limb alignment and appropriate prosthesis .

Outcomes of total knee arthroplasty following high tibial osteotomy.

BACKGROUND: Total knee arthroplasty (TKA) following high tibial osteotomy (HTO) is a technically demanding procedure with varying results. The purpose of our study was to analyze the clinicoradiological results of TKA following HTO and to identify the factors that may influence the final outcome. MATERIALS AND METHODS: 55 patients (58 knees) who had undergone a previous HTO were treated with a TKA from 1991 to 2009. There were 34 female and 21 male patients. The average age was 61.9 years (range 52-82 years) and the average weight was 79.5 kg (range 54-106 kg), with an average body mass index of 29.6 (range 21.8-34.6) at the time of TKA. The knee society scores (KSSs) and knee society functional scores were evaluated for every patient pre and postoperatively and the results evaluated. RESULTS: The mean period of followup was 11.2 years (range 3-18 years) and the patients were followed up every year. The average KSS score at final followup improved from 38.5 (range 0-80 points) preoperatively to 88.5 postoperatively (range 35-95 points) (P < 0.05). The mean femorotibial angle corrected from 6.8 degrees (range 5-12°) varus preoperatively to a valgus of 4.4 (2-8°) degrees postoperatively. The average joint line height improved to an average of 9.6 mm (range 4.4-22 mm) (P < 0.01) at the last followup. The average Insall Salvatti Ratio also improved (average 1.11 preoperative - 1.21 average postoperative) (P < 0.05). The average range of motion improved to 108° (range 85°-125°) from 76° preoperative (range 55°-100°) (P < 0.01). CONCLUSION: Although TKA postHTO is a demanding surgery however, with newer component designs, results are comparable to primary TKA. Technical difficulties in exposure can sometimes lead to component malpositioning, which can affect the final outcome. Inadequate soft tissue balancing and limb malalignment should always be kept in mind. Regular followup to look for evidences of loosening is advised in such patients].

Survivorship Analysis of Closing Wedge Proximal Tibial Osteotomy Using Miniplate Staple

PURPOSE: To evaluate the clinical and radiological results and to analyze the survivorship after closing wedge proximal tibial osteotomy(PTO) using miniplate staple. MATERIALS AND METHODS: From November 1993 to August 2003, sixty closing wedge PTO using miniplate staple were performed in forty patients. The average follow-up period was 7.2 years(range, 2.8~12.5 years). According to the post- operative femorotibial angle(FTA), group I was defined as the cases whose FTA was less than 7 degrees of valgus(25 cases) and group II was defined as the cases whose FTA was more than 7 degrees of valgus(35 cases). The HSS score, FTA and survivorship were compared between group I and II. RESULTS: Average HSS score at the last follow up were 75.3 in group I and 85.9 in group II(p=0.006). Average FTA at the last follow up were 0.8 degrees in group I and 7.7 degrees in group II(p=0.006). The overall 7-year survivorship was 92.6% and 12-year survivorship was 75.5%. The 7-year survivorship and 12-year survivorship of group I were 86.7% and 54.2%, respectively. Group II have no failure at last follow up(p=0.0489). CONCLUSION: Our results suggest that the desirable postoperative FTA was more than 7 degrees of valgus, considering the long term satisfactory result and survivorship of the closing wedge PTO using miniplate staple for the osteoarthritic knees.

Analysis of complications in high tibial valgus osteotomy in the varus osteoarthritic knee: a series of 23 cases / 中国矫形外科杂志

[Objective]To analyze the reasons of complications in high tibial valgus osteotomy in the varus osteoarthritic knee and its management.[Method]We studied the results of valgus-producing high tibial osteotomies in patients who had medial unicompartmental osteoarthritis and varus malalignment.We performed the operation for 126 patients from January 2000 to October 2004.Twenty-one patients had complications,including four men and seventeen women,with average age of 61 years(ranged:48～64 years).The femorotibial angle was measured on the standing anteroposterior film of knee preoperatively in order to get high accuracy in preoperative planning.A lateral closing-wedge osteotomy was performed,the osteotomy site was stabilized by Giebel blade plate or stepped staple.[Result]The mean duration of follow-up was 7.5 months(ranged,6 to 12 months).There were twenty-three complications(21 patients,16.7%):tibial fracture in four cases,deep-vein thrombosis in five cases,peroneal nerve palsy in three cases,recurrence of varus deformity in six cases,internal fixation failure in four cases(recurrence of varus deformity developed in two patients),a superficial wound infection developed in one patient.[Conclusion]To reduce the incidence of complications in high tibial valgus osteotomy,we should make familiarication with anantomy and take more accuracy in preoperative planning,improve surgical skill as well as appropriate perioperative management.