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Bone & Joint Research
Vol. 2, Issue 8 | Pages 155 - 161
1 Aug 2013
Mathew SE Madhuri V

Objectives. The development of tibiofemoral angle in children has shown ethnic variations. However this data is unavailable for our population. Methods. We measured the tibiofemoral angle (TFA) and intercondylar and intermalleolar distances in 360 children aged between two and 18 years, dividing them into six interrupted age group intervals: two to three years; five to six years; eight to nine years; 11 to 12 years; 14 to 15Â years; and 17 to 18 years. Each age group comprised 30 boys and 30 girls. Other variables recorded included standing height, sitting height, weight, thigh length, leg length and length of the lower limb. Results. Children aged two to three years had a valgus angulation with a mean TFA of 1.8° (. sd. 0.65) in boys and 2.45° (. sd. 0.87) in girls. Peak valgus was seen in the five- to six-year age group, with mean TFAs of 6.7° (. sd. 1.3) and 7.25° (. sd. 0.64) for boys and girls, respectively. From this age the values gradually declined to a mean of 3.18° (. sd. 1.74) and 4.43° (. sd. 0.68) for boys and girls, respectively, at 17 to 18 years. Girls showed a higher valgus angulation than boys at all age groups. Conclusion. This study defines the normal range of the TFA in south Indian boys and girls using an easy and reliable technique of measurement with a standardised custom-made goniometer. Cite this article: Bone Joint Res 2013;2:155–61


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_4 | Pages 1 - 1
3 Mar 2023
Kinghorn AF Whatling G Bowd J Wilson C Holt C
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This study aimed to examine the effect of high tibial osteotomy (HTO) on the ankle and subtalar joints via analysis of static radiographic alignment. We hypothesised that surgical alteration of the alignment of the proximal tibia would result in compensatory distal changes. 35 patients recruited as part of the wider Biomechanics and Bioengineering Centre Versus Arthritis HTO study between 2011 and 2018 had pre- and postoperative full-length weightbearing radiographs taken of their lower limbs. In addition to standard alignment measures of the limb and knee (mechanical tibiofemoral angle, Mikulicz point, medial proximal tibial angle), additional measures were taken of the ankle/subtalar joints (lateral distal tibial angle, ground-talus angle, joint line convergence angle of the ankle) as well as a novel measure of stance width. Results were compared using a paired T-test and Pearson's correlation coefficient. Following HTO, there was a significant (5.4°) change in subtalar alignment. Ground-talus angle appeared related both to the level of malalignment preoperatively and the magnitude of the alignment change caused by the HTO surgery; suggesting subtalar positioning as a key adaptive mechanism. In addition to compensatory changes within the subtalar joints, the patients on average had a 31% wider stance following HTO. These two mechanisms do not appear to be correlated but the morphology of the tibial plafond may influence which compensatory mechanisms are employed by different subgroups of HTO patients. These findings are of vital importance in clinical practice both to anticipate potential changes to the ankle and subtalar joints following HTO but it could also open up wider indications for HTO in the treatment of ankle malalignment and osteoarthritis


Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_18 | Pages 7 - 7
14 Nov 2024
Cullen D Thompson P Johnson D Lindner C
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Introduction. Accurate assessment of alignment in pre-operative and post-operative knee radiographs is important for planning and evaluating knee replacement surgery. Existing methods predominantly rely on manual measurements using long-leg radiographs, which are time-consuming to perform and are prone to reliability errors. In this study, we propose a machine-learning-based approach to automatically measure anatomical varus/valgus alignment in pre-operative and post-operative standard AP knee radiographs. Method. We collected a training dataset of 816 pre-operative and 457 one-year post-operative AP knee radiographs of patients who underwent knee replacement surgery. Further, we have collected a separate distinct test dataset with both pre-operative and one-year post-operative radiographs for 376 patients. We manually outlined the distal femur and the proximal tibia/fibula with points to capture the knee joint (including implants in the post-operative images). This included point positions used to permit calculation of the anatomical tibiofemoral angle. We defined varus/valgus as negative/positive deviations from zero. Ground truth measurements were obtained from the manually placed points. We used the training dataset to develop a machine-learning-based automatic system to locate the point positions and derive the automatic measurements. Agreement between the automatic and manual measurements for the test dataset was assessed by intra-class correlation coefficient (ICC), mean absolute difference (MAD) and Bland-Altman analysis. Result. Analysing the agreement between the manual and automated measurements, ICC values were excellent pre-/post-operatively (0.96, CI: 0.94-0.96) / (0.95, CI: 0.95-0.96). Pre-/post-operative MAD values were 1.3°±1.4°SD / 0.7°±0.6°SD. The Bland-Altman analysis showed a pre-/post-operative mean difference (bias) of 0.3°±1.9°SD/-0.02°±0.9°SD, with pre-/post-operative 95% limits of agreement of ±3.7°/±1.8°, respectively. Conclusion. The developed machine-learning-based system demonstrates high accuracy and reliability in automatically measuring anatomical varus/valgus alignment in pre-operative and post-operative knee radiographs. It provides a promising approach for automating the measurement of anatomical alignment without the need for long-leg radiographs. Acknowledgements. This research was funded by the Wellcome Trust [223267/Z/21/Z]


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 128 - 128
1 Mar 2010
Cho S Youm Y Jeong J
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We compared the short term follow-up clinical and radiological results after PCL substituting (PS) Medial Pivot Knee and Nexgen. ®. LPS total knee arthroplasty (TKA). Seventy knees in 48 patients after TKA with PS ADVANCE. ®. Medial Pivot Knee (Group I) and sixty seven knees in 45 patients after TKA with Nexgen. ®. LPS (Group II) were evaluated retrospectively from March 2004 to May 2006. The mean follow up period was 31 months (range: 24–43 months) in group I and 32 month (range: 24–46 months) in group II. All the knees were operated by one surgeon. The evaluations included the preoperative and postoperative range of motion (ROM), Knee society score (KSS), tibiofemoral angle, and postoperative complications. In group I, ROM increased from preoperative mean flexion contracture of 6.3° and further flexion of 116° to postoperative mean flexion contracture 1.9° and further flexion 121°, KS knee score increased from 46 to 87, KS function score increased from 37 to 83, and tibiofemoral angle changed from preoperative varus 4.0° to postoperative valgus 5.5°. In group II, ROM increased from preoperative mean flexion contracture of 13° and further flexion of 118° to postoperative mean flexion contracture 0.9° and further flexion 123°, KS knee score increased from 50 to 87, KS function score increased from 48 to 83, and tibiofemoral angle changed from preoperative varus 4.1° to postoperative valgus 5.3°. The complications were two periprosthetic patellar fracture and one failure of tibial component in group I, and one early failure of femoral component and one arthrofibrosis in group II. There was no statistical difference in radiological and clinical results between the two groups. Minimum 2-year follow-up result of PS Medial Pivot Knee TKA was comparable to that of Nexgen. ®. LPS TKA and longer term follow-up would be necessary


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_18 | Pages 10 - 10
1 Dec 2014
Ghosh K Robati S Shaheen A Solan M
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The MediShoe (Promedics Orthopaedics Ltd, Glasgow) is a specific post-operative foot orthosis used by post-operative foot and ankle patients designed to protect fixations, wounds and maximise comfort. The use of rigid-soled shoes has been said to alter joint loading within the knee and with the popular use of the MediShoe at our centre in post operative foot and ankle surgery patients, it is important to ascertain whether this is also true. An analysis of the knee gait kinetics in healthy subjects wearing the MediShoe was carried out. Ten healthy subjects were investigated in a gait lab both during normal gait (control) and then with one shoe orthosis worn. Force plates and an optoelectronic motion capture system with retroreflective markers were used and placed on the subjects using a standardised referencing system. Three knee gait kinetic parameters were measured:- knee adduction moment; angle of action of the ground reaction force with respect to the ground in the coronal plane as well as the tibiofemoral angle. These were calculated with the Qualisys software package (Gothenburg, Sweden). A two-tailed paired t-test (95% CI) showed no significant difference between the control group and the shoe orthosis-fitted group for the knee adduction moment (p = 0.238) and insignificant changes with respect to the tibiofemoral angle (p = 0.4952) and the acting angle of the ground reaction force (p = 0.059). The MediShoe doesn't significantly alter knee gait kinetics in healthy patients. Further work, however is recommended before justifying its routine use


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_1 | Pages 79 - 79
1 Jan 2016
Cho S Youm Y Kim J
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Purpose. The NexGen® legacy posterior stabilized (LPS)-Flex total knee system (Zimmer, Warsaw, IN) is designed to provide 150° of flexion following total knee arthroplasty (TKA). But, recent reports found a high incidence of loosening of the femoral component related to the deep flexion provided. We evaluated 9- to 12-year clinical and radiological follow-up results after NexGen® LPS-Flex TKA. Materials and Methods. A retrospective evaluation was undertaken of 209 knees in 160 patients (21 males, 139 females) who were followed up for more than 9 years after Nexgen®LPS-Flex TKA. Evaluations included preoperative and postoperative range of motion(ROM), Knee Society(KS) knee score, function scores, tibiofemoral angle and assessment of postoperative complications. Results. The NexGen® LPS-Flex TKA resulted in a significant ROM increase from a mean flexion contracture of 9°(range 0°–20°) and further flexion of 117°(range 80° –155°) to a mean flexion contracture of 2°(range 0° –10°) and a further flexion of 131°(range 95° –155°). The KS knee and function scores significantly improved from 52 and 38 before surgery to 87 and 82 after surgery, respectively. The tibiofemoral angle significantly improved from varus 5.7° to valgus 5.4°. Progressive radiolucent lines around the femoral component on radiographs were observed in 39 knees(18.7%, 34 patients), and more of those knees, could squat than non-radiolucent knees(74.4% vs. 25.6%; P<0.05). Twelve knees(5.7%, 11 patients) were revised at a mean 53 months after the index operation due to loosening of the femoral component. Other causes of revision included 3 knees of infection(1.4%) and 3 knees of instability(1.4%). Conclusion. While NexGen® LPS-Flex TKA satisfactorily improved ROM, it was associated with a relatively high incidence of loosening of the femoral components. This might be associated with passive-maximal flexion activity, such as squatting or kneeling. The clinical relevance of this study is that squatting or kneeling, common activity in Asian, may not be allowed after NexGen® LPS-Flex TKA


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_2 | Pages 104 - 104
1 Jan 2016
Cho S Youm Y Kim J
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Purpose. The purpose of this study was to compare the clinical and radiological results after total knee arthroplasty(TKA) with PCL sacrificing (PCS) Medial Pivot Knee (MPK) and PCL Substituting (PS) Nexgen® LPS. Materials and Methods. One hundred twenty knees in 80 patients after TKA with PCS ADVANCE® MPK (Group I) and 116 knees in 85 patients with PS Nexgen® LPS (Group II) were retrospectively evaluated. All the patients were followed up for more than 6 years. The evaluations included preoperative and postoperative range of motion (ROM), tibiofemoral angle, Knee Society (KS) knee and function score, Hospital for Special Surgery (HSS) knee score, WOMAC score and postoperative complications. Results. For group I, the ROM increased from a mean flexion contracture of 7.6° and further flexion of 115.1° to 1.3° and 120.5° respectively and for group II, from 9.4° and 124.8° to 1.3° and 129.7°, respectively. For group I, KS knee and function scores increased from 46 and 38 to 87 and 82 respectively, and for group II, from 49 and 43 to 88 and 81, respectively. Hospital for Special Surgery (HSS) knee score improved from preoperatively 48.3 to postoperatively 84.2 for group I and 44.6 to 82.3 for group II. WOMAC score was improved preoperatively 54.8 to postoperatively 18.3 for group I and 57.4 to 17.4 for group II. For group I, tibiofemoral angle changed from varus 4.6° to valgus 5.8° and for group II, from varus 5.8° to valgus 5.2°. The complications were 2 cases(1.7%) of periprosthetic patellar fracture and 1 case(0.8%) of early failure of the tibial component and 1 case(0.8%) of osteolysis and loosening in group I, and 1 knee (1.0%) with early femoral component failure and 1 knee with arthrofibrosis (1.0%) in group II. Conclusion. The minimum 6-year follow-up results of PCS ADVANCE® MPK TKA without box cut were comparable to those of PS Nexgen®LPS


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_7 | Pages 74 - 74
1 May 2016
Kang S Chang C Choi I Woo J Woo M Kim S
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Introduction. Deformity of knee joint causes deviation of mechanical axis in the coronal plane, and the mechanical axis deviation also could adversely affect biomechanics of the ankle joint as well as the knee joint. Particularly, most of the patients undergoing total knee arthroplasty (TKA) have significant preoperative varus malalignment which would be corrected after TKA, the patients also may have significant changes of ankle joint characteristics after the surgery. This study aimed 1) to examine the prevalence of coexisting ankle osteoarthritis (OA) in the patients undergoing TKA due to varus knee OA and to determine whether the patients with coexisting ankle OA have more varus malalignment, and 2) to evaluate the changes of radiographic parameters for ankle joint before and 4 years after TKA. Methods. We evaluated 153 knees in 86 patients with varus knee OA who underwent primary TKA. With use of standing whole-limb anteroposterior radiographs and ankle radiographs before and 4 years after TKRA, we assessed prevalence of coexisting ankle OA in the patients before TKA and analyzed the changes of four radiographic parameters before and after TKA including 1) the mechanical tibiofemoral angle (negative value = varus), 2) the ankle joint orientation relative to the ground (positive value = sloping down laterally), 3) ankle joint space, and 4) medial clear space. Results. Of the 153 knees, 59 (39%) had radiographic ankle OA. The knees with ankle OA had significantly more varus mechanical tibiofemoral angle preoperatively than those without ankle OA (− 11.9° vs. − 9.3° on average, respectively; P = 0.003). Compared to the preoperative condition, the ankle joint orientation relative to the ground significantly changed after TKA (from 9.0° to 4.8° on average, P<0.001) while ankle joint space and medial clear space did not. Conclusions. Our study revealed that coexisting ankle OA would be common in patients with varus knee OA, particularly in patients with more varus malalignment. TKA also significantly changes the ankle joint orientation relative to the ground which shows more parallel to the ground. However, its effect on ankle joint space and medial clear space seems to be minimal upto 4 years after TKA. Our findings warrant consideration in preoperative evaluations of ankle OA in varus knee OA patients undergoing TKA, and further studies should evaluate prospectively the clinical implications of radiographic change of the ankle joint after TKA


Orthopaedic Proceedings
Vol. 86-B, Issue SUPP_III | Pages 262 - 262
1 Mar 2004
Hopgood P Mitchell S Sochart D Rae P
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Aim: The aim of this research was to assess the difference in the observed tibiofemoral axis between long leg and short AP films of the knee. Method: 20 patients who were undergoing primary total knee replacement, and had had no previous surgery on the affected limb were x-rayed using the a long leg cassette to include both the hip and ankle joints. A special screen was constructed to obscure all the x-ray except for a field, the size of a standard AP x-ray of the knee. The tibiofemoral angle was measured by two independent observers first on the short film and then on the long leg film. Results: Our results have shown that the short leg film consistently overestimates the true tibiofemoral angle. Intraobserver correlation is also better when comparing the long leg film rather than the short film. Conclusion: Measurement of the tibiofemoral or anatomical axis of the knee is best performed using long leg films, as this appears to give more consistent and reproducible results


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 161 - 162
1 Mar 2010
Lee S Seong S Kim D Lee M
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Constrained condylar knee (CCK) prosthesis offers an implant option for complex revision total knee arthroplasties in which stable varus-valgus constraint as well as rotational control is needed for severe bone defect and ligament insufficiency. The aim of this study was to evaluate the clinical and radiological outcome of CCK prosthesis in revision TKA. Fify-one revision TKAs performed using CCK prosthesis between Jan. 1998 and Feb. 2006 were performed. The mean follow-up period was 5 years and 3 months (2 to 9 years) and the interval between initial and revision TKA was 8 years (4 months to 21 years). The mean age was 67 years. Range of motion (ROM), knee society (KS) score, hospital for special surgery (HSS) score, complication rate and failure rate was evaluated. The tibiofemoral angle and radiolucent line was also evaluated on plain radiograph. The mean ROM improved from 81.9° to 102°. The mean KS score improved from 49.3° to 79.7°, and KS function score from 50.3 to 71.0 (P< .001). The mean HSS score improved from 50.7 to 78.7 (P< .001). Tibiofemoral angle improved from valgus 3.1° to valgus 5.6° (P< .001). Radiolucent line more than 2mm was observed around 4 femoral and 4 tibial components. Complications including 1 skin necrosis, 1 tibial tubercle nonunion, 2 infections, 3 periprosthetic fractures and 5 arthrofibrosis were observed. Overall rating was excellent or good in 88% at the last follow up. Revision TKA using CCK prosthesis showed comparable results with other reports in average 5 years follow-up


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 131 - 131
1 Mar 2010
Cho S Youm Y Jeong J
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We evaluated the minimum 3 year follow-up clinical and radiological results after Nexgen. ®. LPS-flex total knee arthroplasty (TKA). Two hundred eighteen knees in 166 patients, who could be followed up more than 3 years after Nexgen. ®. LPS-flex TKA from October 2001 to February 2005, were evaluated retrospectively. The average age was 64.2 years. Twenty-two patients were male and 144 patients were female. The mean follow-up period was 51 months (range 36–73 months). The evaluations included the preoperative and postoperative range of motion (ROM), Knee Society (KS) Score, tibiofemoral angle and postoperative complications. The ROM increased from preoperative mean flexion contracture of 8.7° and further flexion of 117.3° to postoperative mean flexion contracture of 1.8° and further flexion of 131.3°. The KS knee score and function score improved from 52 and 38 before surgery to 87 and 82 after surgery, respectively. The tibiofemoral angle changed from preoperative varus 5.7° to postoperative valgus 5.4°. The complications were 30 knees (13.8%, 27 patients) of early loosening of the femoral component on X-ray, 2 instabilities, 2 periprosthetic fractures and 1 failure of extensor mechanism. Early loosening (30 knees) was found at mean 24 months after operation. Among these cases, 23 knees were able to squat, 5 knees to flex over 130°, 1 knee upto 115° and 1 knee upto 95°. Seven knees (3.2%, 6 patients) were revised at mean 49 months after index operation. The results after Nexgen. ®. LPS-flex TKA were satisfactory in terms of ROM, but relatively high incidence of early loosening of the femoral components occurred, which might be associated with passive-maximal flexion activity, such as squatting or kneeling


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_I | Pages 117 - 117
1 Mar 2010
Choy W Kim K Ko J
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Purpose: To analyze the clinical and radiographic results of patients treated by Oxford minimally invasive unicompartmental knee arthroplasty. Materials and Methods: We have operated 166 patients 188 knees of minimally invasive unicompartmental knee arthroplasty(Oxford Uni. ®. ) from January 2002 to December 2005. The mean ages was 65.3 (44–82) years and 16 cases of male and 150 cases of female. The mean follow-up period was 57 (36–77) months. Preoperative diagnosis were osteoarthritis in 166 cases, avascular necrosis of medial femoral condyle in 20 cases and chondrocalcinosis in 2 cases. The clinical results were evaluated using the HSS knee score and the range of motion of knee preoperatively and at the final follow up. At the final follow up, the ability of the patient to assume the squatting and cross-leg position were checked. The tibiofemoral angle was measured preoperatively and postoperatively. Component loosening, radiolucent lines were checked. Result: The HSS knee score was 67.5 (52–86) preoperatively and 89.9 (59–100) at the final follow up. The mean preoperative flexion contracture was 6.5° (0–20) and 0.81 (0–5) at the final follow up. Active full flexion was possible within postoperative 2 months. The squatting position was possible in 133 patients (80.1%) and the cross-leg position was possible in 152 patients (91.6%). The tibiofemoral angle was improved varus 1.5° to valgus 4.8°. Complication occurred in 14 cases (7.4%). Meniscal bearing dislocation in 8 cases (4.3%). Tibial components loosenig in 3 cases (1.6%). Femoral components loosening in 2 cases (1.1%). The average time of meniscal bearing dislocation was 11.3 (3–24)months postoperatively. Six cases returned to the predislocation level of activity with the insertion of thicker bearings and 2cases required TKR conversion. Conclusion: Minimally invasive unicompartmental knee arthroplasty(Oxford Uni. ®. ) provides rapid recovery, good pain relief and excellent function quite suitable to Korean life-style. But given the high complicate rate in mid-term results. Oxford Uni. ®. gives less reliability compared with TKR


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 91 - 91
1 Dec 2013
Plate JF Augart MA Bracey D Von Thaer S Allen J Sun D Poehling G Jinnah R
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Introduction. There has been renewed interest in the use of unicompartmental knee arthroplasty (UKA) for patients with limited degenerative disease of the knee due to improved surgical techniques and prosthetic design, and the desire for minimally invasive surgery. However, patient satisfaction following UKA for lateral compartment disease have been suboptimal with increased revision rates. Robotic-assisted UKA has been shown to improve precision and accuracy of component placement, which may improve outcomes of lateral UKA. The purpose of this study was to compare the outcome of robotic-assisted UKA to conventional UKA for degenerative disease of the lateral compartment with the hypothesis that robotic-assisted lateral UKA results in superior outcomes compared to conventional UKA. Methods. The institution's joint registry was searched for patients who underwent UKA for limited degenerative disease of the lateral knee compartment between 2004 and 2012 and a total of 125 lateral UKAs were identified. The medical records of all patients were reviewed and assessed for the type of surgical procedure used (robotic-assisted versus conventional), length of hospital stay, Oxford knee score, and occurrence of revision surgery. Preoperative and postoperative radiographs were assessed for tibiofemoral angle, femoral and tibial joint line angle, posterior tibial slope, and orientation of the femoral and tibial components. Results. A total of 88 (84 patients) robotic-assisted (Figure 1) and 37 (36 patients) conventional UKA (Figure 2) were analyzed and compared. Patient age and BMI were similar between patients with robotic-assisted (64.2 ± 11.5 years, 28.7 kg/m. 2. ) and conventional UKA (64.2 ± 11.5 years [p = 0.998], 30.5 kg/m. 2. [p = 0.107]). At a mean follow-up of 24.4 ± 1.1 months for robotic-assisted UKA and 64.0 ± 3.0 months (p < 0.05) for conventional UKA, the mean Oxford scores were significantly higher in patients with robotic-assisted UKA (39.4 ± 1.1 versus 34.4 ± 2.5, p = 0.048). The length of stay was significantly shorter after robotic-assisted UKA (1.7 days) compared to conventional UKA (2.3 days, p < 0.001). Correction of the tibiofemoral angle was significantly higher in patients with conventional UKA (8.7 to 176.9 degrees) compared to patients with robotic-assisted UKA (3.4 to 174.3 degrees, p < 0.001). However, the femoral component was in significantly greater varus position in conventional UKA (98.7 degrees) compared to robotic-assisted UKA (88.2 degrees, p < 0.001). There were significantly more revisions in the conventional UKA group (7 conversions to total knee arthroplasty, 2 tibial component exchanges) compared to robotic-assisted UKA (2 conversions to TKA, p < 0.001). Discussion. The findings of this study revealed a decreased revision rate in robotic-assisted lateral UKAs compared to conventional lateral UKA. Furthermore, patients who received robotic-assisted UKAs had a shorter postoperative hospital stay compared to patients who received conventional UKA. Implant orientation was improved in robotic-assisted UKA compared to conventional UKA. UKA is a technically challenging procedure with limited joint visualization and malaligned components may lead to impaired joint biomechanics causing pain and disease progression to other knee compartments. Robotic-assisted UKA systems offer increased accuracy of component placement with objective soft-tissue balancing which may improve the long-term survival of UKA in patients with limited lateral degenerative disease


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_1 | Pages 49 - 49
1 Feb 2020
Gustke K Morrison T
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Introduction. In total knee arthroplasty (TKA), component realignment with bone-based surgical correction (BBSC) can provide soft tissue balance and avoid the unpredictability of soft tissue releases (STR) and potential for more post-operative pain. Robotic-assisted TKA enhances the ability to accurately control bone resection and implant position. The purpose of this study was to identify preoperative and intraoperative predictors for soft tissue release where maximum use of component realignment was desired. Methods. This was a retrospective, single center study comparing 125 robotic-assisted TKAs quantitatively balanced using load-sensing tibial trial components with BBSC and/or STR. A surgical algorithm favoring BBSC with a desired final mechanical alignment of between 3° varus and 2° valgus was utilized. Component realignment adjustments were made during preoperative planning, after varus/valgus stress gaps were assessed after removal of medial and lateral osteophytes (pose capture), and after trialing. STR was performed when a BBSC would not result in knee balance within acceptable alignment parameters. The predictability for STR was assessed at four steps of the procedure: Preoperatively with radiographic analysis, and after assessing static alignment after medial and lateral osteophyte removal, pose capture, and trialing. Cutoff values predictive of release were obtained using receiver operative curve analysis. Results. STR was necessary in 43.5% of cases with medial collateral ligament (MCL) release being the most common. On preoperative radiographs, a medial tibiofemoral angle (mTFA) ≤177° predicted MCL release (AUC = 0.76. p< 0.01) while an mTFA ≥188° predicted ITB release (AUC = 0.79, p <0.01). Intraoperatively after removal of osteophytes, a robotically assessed mechanical alignment (MA) ≥8° varus predicted MCL release (AUC = 0.84. p< 0.01) while a MA ≥2° valgus (AUC = 0.89, p< 0.01) predicted ITB release. During pose-capture, in medially tight knees, an extension gap imbalance ≥2.5mm (AUC = 0.82, p <0.01) and a flexion gap imbalance ≥2.0mm (AUC = 0.78, p <0.01) predicted MCL release while in laterally tight knees, any extension or flexion gap imbalance >0 mm predicted ITB release (AUC = 0.84, p <0.01 and AUC = 0.82, p <0.01 respectively). During trialing, in medially tight knees, a medial>lateral extension load imbalance ≥18 PSI (AUC = 0.84. p< 0.01) and a flexion load imbalance ≥ 35 PSI (AUC = 0.83, p< 0.01) predicted MCL release while, in laterally tight knees, a lateral>medial extension load imbalance ≥3 PSI (AUC = 0.97, p< 0.01) or flexion load imbalance ≥ 9.5 PSI (AUC = 0.86, p< 0.01) predicted ITB release. Of all identified predictors, load imbalance at trialing had the greatest positive predictive value for STR. Conclusion. There are limitations to the extent that TKA imbalance that can be corrected with BBSC alone if one has a range of acceptable alignment parameters. The ability to predict STR improves from pose-capture to trialing stages during detection of load imbalance. Perhaps this may be due to posterior osteophytes that are still present at pose capture. Further investigation of the relationship between the presence, location and size of posterior osteophytes and need for STR during TKA is necessary


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 88 - 88
1 Apr 2019
Kang SB Chang MJ Chang CB Yoon C Kim W Shin JY Suh DW Oh JB Kim SJ Choi SH Kim SJ Baek HS
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Background. Authors sought to determine the degree of lateral condylar hypoplasia of distal femur was related to degree of valgus malalignment of lower extremity in patients who underwent TKA. Authors also examined the relationships between degree of valgus malalignment and degree of femoral anteversion or tibial torsion. Methods. This retrospective study included 211 patients (422 lower extremities). Alignment of lower extremity was determined using mechanical tibiofemoral angle (mTFA) measured from standing full-limb AP radiography. mTFA was described positive value when it was valgus. Patients were divided into three groups by mTFA; more than 3 degrees of valgus (valgus group, n = 31), between 3 degrees of valgus to 3 degrees of varus (neutral group, n = 78), and more than 3 degrees of varus (varus group, n = 313). Condylar twisting angle (CTA) was used to measure degree of the lateral femoral condylar hypoplasia. CTA was defined as the angle between clinical transepicondylar axis (TEA) and posterior condylar axis (PCA). Femoral anteversion was measured by two methods. One was the angle formed between the line intersecting femoral neck and the PCA (pFeAV). The other was the angle formed between the line intersecting femoral neck and clinical TEA (tFeAV). Tibial torsion was defined as a degree of torsion of distal tibia relative to proximal tibia. It was determined by the angle formed between the line connecting posterior cortices of proximal tibial condyles and the line connecting the most prominent points of lateral and medial malleolus. Positive values represented relative external rotation. Negative values represented relative internal rotation. Results. Greater lateral femoral condylar hypoplasia was related to increased valgus alignment of lower extremity. Correlation coefficient between mTFA and CTA was 0.253 (p < 0.001). Valgus group showed increased CTA, which was 10.2° ± 1.9°. CTA was 7.4° ± 2.5° in neutral group and 6.6° ± 4.8° in varus group. There was significant positive correlation between the degree of valgus alignment and the degree of femoral anteversion (r = 0.145, p = 0.003). pFeAV was 16.7° ± 5.8° in valgus group, 12.1° ± 6.0° in neutral group and 10.9° ± 7.0° in varus group. There was no correlation between degree of valgus alignment and degree of femoral anteversion (r = 0.060, p = 0.218). In terms of tibial torsion, increased valgus malalignment was associated with increased tibial torsion (r = 0.374, p < 0.001). Valgus group showed increased tibial torsion than other groups. Tibial torsion was 32.6° ± 6.2° in valgus group, 26.3° ± 6.9° in neutral group and 22.6° ± 7.2° in varus group. Conclusions. Increased valgus alignment of lower extremity was related to greater lateral femoral condylar hypoplasia. However, increased valgus alignment was not related to degree of femoral anteversion whereas it was related to increased external tibial torsion. Our findings should be considered when determining proper rotational alignment in TKA


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_13 | Pages 9 - 9
1 Jun 2017
Wright J Calder P
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Background. Severe infantile Blount's disease can result in a multiplanar deformity of the proximal tibia with both intra-articular and metaphyseal components. Correction can represent a significant surgical challenge. We describe our results using the Taylor spatial frame for acute tibial hemiplateau elevation combined with gradual metaphyseal correction in patients with severe infantile blounts with an associated physeal bony bar. Methods. Eight patients (10 knees) underwent tibial hemiplateau elevation and metaphyseal correction with use of the Taylor Spatial Frame between 2012–2016. We undertook a retrospective case note and radiographic review of all patients to assess clinical and radiographic outcomes. Mean age at the time of surgery of was 11.7 years and mean length of follow up was 16.8 months. Results. At time of latest follow up all patients reported no hip, knee or ankle pain. All knees were clinically stable without lateral thrust during gait. Improvement in radiographic parameters was seen in all patients. The mean tibiofemoral angle improved from −28.3 to 5.9 degrees post operatively. The angle between femoral condyles and the tibial shaft improved from a mean of 56.3 degrees to 90.3 degrees. The joint depression angle was also seen to improve from mean 47.4 degrees to 9.8 degrees. No significant complications were seen. Conclusion. This technique has been shown to be an effective method of correction of the complex deformity encountered in severe infantile Blount's disease. Use of the Taylor spatial frame may provide certain advantages in comparison to previously described approaches. Level of Evidence: Level IV (Case Series)


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 111 - 111
1 Feb 2017
Chun C Chun K Baik J Lee S
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Background. This study was conducted to assess the clinical and radiologic results of total knee arthroplasty (TKA) with an allogenic bone graft using varus-valgus constrained (VVC) prostheses in knees with severe bone defects and unstable neuropathy. Methods. This study included 20 knees of 16 patients who underwent TKA between August 2001 and January 2006 due to unstable knees with severe bone destruction resulting from neuropathic arthritis. At the time of surgery, the mean age of the patients was 56 years. The mean length of the follow-up period was 10.7 years. A VVC condylar prosthesis was used with an allogenic femoral head graft to reconstruct large bony defects. Clinical results were evaluated using the Hospital for Special Surgery (HSS), Knee Society (KS) function, and Western Ontario and McMaster Universities Osteoarthritis (WOMAC) scores. Three-dimensional computed tomography (3D-CT) was used to evaluate the radiological parameters, which included the tibiofemoral angle, loosening or osteolysis of components, and incorporation of the bone graft. Results. The preoperative mean HSS, KS function, and WOMAC scores were 40.5, 43.2, and 78.3, respectively, and these scores improved to 86.0, 64.6, and 33.8 at the final follow-up. The mean postoperative alignment was 6.1° of valgus angulation. One knee had instability, another knee had partial bony absorption, which was confirmed using 3D-CT, and the other 18 cases (90%) had satisfactory results. No cases experienced radiolucency, fracture, or infection. Conclusions. TKA with an allogenic bone graft using a VVC prosthesis provides a viable option for the treatment of severe bone defects with soft tissue insufficiency in neuropathic knee arthropathy. Level of Study: Level IV, therapeutic study


Orthopaedic Proceedings
Vol. 88-B, Issue SUPP_II | Pages 284 - 284
1 May 2006
Taylor C Brady P Walsh M O’Meara A Moore D Dowling F Fogarty E
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Introduction: Therapeutic bone marrow transplantation has increased survival in Hurler syndrome, but the effects on musculoskeletal development remain unclear. Long term reports on mobility are poor, with many patients gradually losing walking ability in later childhood secondary to hip subluxation and joint contractures. As previous cohorts are small, data is limited. Methods: We detail the follow up of twenty patients over a mean of 94 months (range 1 – 17.4 years). Radiographs were assessed for hip dysplasia using acetabular angle of Sharp, centre edge angle of Wiberg and tibiofemoral shaft angle. Clinical examination was performed at an annual multidisciplinary assessment by one clinician and compared against age matched controls. 3D gait analysis was performed on eight older children, and deviance in kinematic variables was plotted against controls with Mann-Whitney U test for statistical analysis. Results: All patients demonstrated characteristic ace-tabular dysplasia. Fourteen patients have undergone containment surgery at a mean of 4.4 years. Innominate osteotomy is an essential part of this. Mean preoperative acetabular angle was reduced from 34 ± 4° to 22 ± 3°. Femoral head containment is maintained, with mean centre edge angle in older patients 39 ± 7°. Genu valgum is observed early, and five patients underwent medial epiphyseal stapling at a mean of 7.8 years, decreasing tibiofemoral angle by a mean of 8.0°. All patients are currently independently mobile, with restriction of internal hip rotation being the only significant clinical finding (P< 0.001). Joint contractures were not noted. Walking speed and stride length were comparable to controls, but endurance is reduced by about one quarter. Gait analysis demonstrates a characteristic pattern, with anterior pelvic tilt secondary to thoracolumbar gibbus, relative hip flexion throughout the gait cycle, valgus knees and compensatory pronated feet; all measured deviations were significant (P< 0.001). Conclusions This large group maintained successful hip containment and good mobility throughout childhood. Innominate osteotomy alone has been used recently. Despite plain film appearance, genu valgum is a functional problem in gait, and we would anticipate greater use of corrective stapling in the future. This is the first report of gait analysis in Hurler syndrome, and features specific to the condition are described


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_4 | Pages 12 - 12
1 Jan 2016
Song IS Shin SY
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Purpose. We may consider total knee arthroplasty on one knee and unicompartmental knee arthroplasty on another knee when the patient has different grade osteoarthritis on one knee and opposite knee. Both total knee and unicompartmental knee arthroplasty had been reported as excellent clinical results, but there can be different results and different preference if the same patient undergo operation of simulataneous total knee and unicompartmental knee. We performed total and unicompartmental knee arthroplasty and pretend to report results of the clinical and radiological results and rationale of the operation. Materials and Methods. From Marth 2007 to February 2014, 23 patients, 46 knees that underwent total knee arthroplasty and unicompartmental knee arthroplasty on knees with different osteoarthritis grade in same person enrolled in this study(Fig. 1). The mean age was 64.4 years old(range:55–75) and mean follow-up period was 25.1 months(range:13–72). Results. The tibiofemoral angle changed from 4.0 of varus to 5.4 of valgus in the total knee arthroplasty, and from 0.5 of valgus to 3.8 of valgus in the unicompartmental knee arthroplasty. The mechanical axis deviation changed from varus 28.35mm to varus 3.68mm in the total knee arthroplasty, and from 16.42 to 8.81 in the unicompartmental knee arthroplasty. The average Hospital for Special Surgery Knee-Rating Scale(HSS) improved from 55.1 preoperatively to 93.4 at last follow-up in the total knee arthroplasty, and from 65.2 to 95.2 in the unicompartmental knee arthroplasty. The average WOMAC Score improved from 61.6 preoperatively to 18.0 at last follow-up in the total knee arthroplasty, and from 55.4 to 16.2 in the unicompartmental knee arthroplasty. For patient preference, 5 patients(22%) preferred the unicompartmental knee arthroplasty, and 6 patients(26%) preferred the total knee arthroplasty, and 12 patients felt no difference between two knees. 20 patients(87%) reported being ‘very satisfied’ or ‘satisfied’ in the total knee arthroplasty, and 18 patients(79%) reported in the unicompartmental knee arthroplasty. We underwent 1 case complication of tibial implant loosening and varus malalignment. So, we converted total knee arthroplasty about 3 months later(Fig. 2). Conclusions. Total knee arthroplasty and unicompartmental knee arthroplasty in same person showed satisfactory clinical and radiological results. There was no difference in preference site and postoperative range of motion showed more regainment on unicompartmental knee arthroplasty. More complications were demonstrated in unicompartmental knee arthroplasty. Total and unicompartmental knee arthroplasty in same person seems to be a good option when the both knee have different osteoarthritis grade


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_12 | Pages 43 - 43
1 Mar 2013
El-nahas W Nwachuku I Khan K Hodgkinson J
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Clinical success of total knee arthroplasty is correlated with correct orientation of the components. Controversy remains in the orthopaedic community as to whether the intramedullary or extramedullary tibial alignment guide is more accurate in the tibial cut. Is there any difference between intramedullary and extramedullary jigs to achieve better accuracy of the tibial components in total knee replacements?. A retrospective study done on 100 patients during the time period 2007 to 2010. The 100 knee replacements were done by the same surgeon, where 50 patients had the intramedullary tibial alignment guide and the other 50 had the extramedullary one. The tibiofemoral angle was measured pre-operatively as well as post operatively, the tibial alignment angle was measured post operatively then the results were statistically analysed using the SPSS. There was no significant difference between both groups regarding the tibial alignment angles. Both techniques proved accurate in producing an acceptable post operative tibial component alignment angle. We recommend orthopaedic surgeons choose either technique knowing that accuracy levels are similar. The debate between intramedullary and extramedullary tibial cutting jigs/guides/ devices continues and most orthopaedic surgeons will use their preferred technique and will continue to achieve good post operative results as we have found in our centre. Our study is rare due to the fact we have a single surgeon performing both techniques, therefore controlling for any surgical experience or operating technique differences