Abstract. Extended Trochanteric Osteotomy (ETO) improves surgical exposure and aids femoral stem and bone cement removal in Revision Total Hip Replacement (RTHR) surgery. The aim of this study was to identify healing rates and complications of ETO in RTHR. Methods. From 2012 to 2019 we identified patients who underwent ETO for RTHR. Data collected demographics, BMI, diabetes, anticoagulants, indication for ETO, surgical approach, length of ETO and complications. Descriptive analysis of patient demographics, multiple linear regression analysis was performed to assess ETO complications. Results. There were 63 patients with an average age of 69 years. Indications for ETO were aseptic loosening (30), infection (15), periprosthetic fracture (9), recurrent dislocation (5), broken implant (4). There were 44 cemented and 19 uncemented femoral stem that underwent ETO. Average time from index surgery was 12 years (less than a year to 38 years). All procedures were through posterolateral approach and all ETO were stabilised with cables. Average length of ETO was 12.5cm. BMI varied from 18 to 37. There were 5 diabetics and 16 on anticoagulants. All but one ETO went on to unite. Other complications included infection, dislocations, lateral thigh pain and significant limp. Discussion. Fixation of ETO can be with either wires or cables or plate with cables/screws. Advantages of cables are no irritation over greater trochanter, no disruption of gluteus medius/vastus lateralis continuity, reproducible tension in cables and use of torque limiter minimises loss of tension in cables

Introduction. The influences of posterior tibial slope on the knee kinematics have been reported in both TKA and UKA. We hypothesized the posterior tibial slope (PTS) would affect the sagittal knee alignment after UKA. The influences of PTS on postoperative knee extension angle were investigated with routine lateral radiographies of the knee after UKA. Materials & Methods. Twenty-four patients (26 knees; 19 females, 7 males) underwent medial UKA were involved in this study. Average age was 74.8 ± 7.2 years. The mean preoperative active range of motion were − 4.1° ± 6.3°in extension and 123.2° ± 15.5° in flexion. All UKAs were performed using fixed bearing type UKA (Zimmer Biomet, ZUK), with adjusting the posterior slope of the proximal tibial bone cut according to the original geometry of the tibia. Routine lateral radiographies of the knee were examined preoperatively, 6 months after the surgery. PTS and knee extension angles with maximal active knee extension (mEXT) and one-leg standing (sEXT) were radiographically measured. We used the fibular shaft axis (FSA) for the sagittal mechanical axis of the tibia. PTS was defined as the angle between the medial tibial plateau and the perpendicular axis of FSA. Extension angles (mEXT and sEXT) were defined as the angles between FSA and distal femoral shaft axis (positive value for hyperextension). The changes of PTS and the influences of PTS on sEXT at each time period were analyzed using simple linear regression analysis (p<0.05). Results. The mean PTSs were 10.0° ± 3.0° and 9.9° ± 2.7° preoperatively, 6m after surgery respectively. The mean mEXTs were −4.1° ± 6.3° and −2.0° ± 5.4°, and sEXTs were −9.4° ± 7.6° and −7.3° ± 6.7° at each time period. Preoperative and postoperative PTS had positive correlation (r = −0.65). PTS significantly negatively correlated to sEXT at 6 months after the surgery (r = −0.63). Discussions. We found patient tended to stand with slight knee flexion (sEXT) which was smaller than the flexion contracture measured by mEXT. Interestingly, postoperative PTS significantly correlated to the knee flexion angle during one-leg standing. Patients with the higher PTS after UKA were more likely to stand with the higher knee flexion. The higher PTS had been reported to increase tibial anterior translation and strain or tear of the anterior cruciate ligament with load bearing in the normal knee. Slight knee flexion during one-leg standing would be beneficial to keep the joint surface parallel to the ground depending on PTS and reduce the anterior shearing force on the tibia after UKA. Conclusion. Postoperative posterior tibial slope reduced knee extension angle during one-leg standing after UKA. For any figures or tables, please contact authors directly

Purpose. We sought to determine whether there was a difference in the posterior condylar offset (PCO), posterior condylar offset ratio (PCOR) following total knee arthroplasty (TKA) with anterior referencing (AR) or posterior referencing (PR) systems. We also assessed whether the PCO and PCOR changes, as well as patient factors were related to range of motion (ROM) in each referencing system. In addition, we examined whether the improvements in clinical outcomes differed between the two referencing systems. Methods. This retrospective study included 130 consecutive patients (184 knees) with osteoarthritis who underwent primary posterior cruciate ligament (PCL)-substituting fixed-bearing TKA. All patients were categorized into the AR or PR group according to the referencing system used. Radiographic parameters, including PCO and PCOR, were measured using true lateral radiographs. The difference between preoperative and postoperative PCO and PCOR values were calculated. Clinical outcomes including ROM and Western Ontario and McMaster University (WOMAC) scores were evaluated preoperatively and at 2 years after TKA. The PCO, PCOR values, and clinical outcomes were compared between the two groups. Furthermore, multiple linear regression analysis was performed to determine the factors related to postoperative ROM in each referencing system. Results. The postoperative PCO was greater in the AR group (28.4 mm) than in the PR group (27.4 mm), whereas the PCO was more consistently preserved in the PR group. In contrast, there was no difference in the mean postoperative PCOR between the two groups. The mean postoperative ROM after TKA was greater in the AR group (129°) than in the PR group (122°), whereas improvement in WOMAC score did not differ between the two groups. Preoperative ROM was the only factor related to postoperative ROM in both groups. Conclusions. The postoperative PCO was greater in the AR group, whereas the PCO was more consistently preserved after surgery in the PR group. The postoperative PCO and PCOR changes did not affect the postoperative ROM, regardless of the referencing system used after PCL-substituting fixed-bearing TKA. Furthermore, similar clinical outcomes were achieved in the AR and PR groups

Aims. Metal-on-metal total hip replacements (MoM THRs) are frequently revised. However, there is a paucity of data on clinical outcomes following revision surgery in this cohort. We report on outcomes from the largest consecutive series of revisions from MoM THRs and consider pre-revision factors which were prognostic for functional outcome. Materials and Methods. A single-centre consecutive series of revisions from MoM THRs performed during 2006–2015 was identified through a prospectively maintained, purpose-built joint registry. The cohort was subsequently divided by the presence or absence of symptoms prior to revision. The primary outcome was functional outcome (Oxford Hip Score (OHS)). Secondary outcomes were complication data, pre- and post-revision serum metal ions and modified Oxford classification of pre-revision magnetic resonance imaging (MRI). In addition, the study data along with demographic data was interrogated for prognostic factors informing on post-revision functional outcome. Results. 180 revisions in 163 patients were identified at a median follow-up of 5.48 (2–11.7) years. There were 152 (84.4%) in the symptomatic subgroup and 28 (15.6%) in the asymptomatic group. Overall median OHS improved from 29 to 37 with revision (P<0.001). Symptomatic patients experienced greater functional benefit (DOHS 6.5 vs. 1.4, p=0.012) compared to asymptomatic patients, though they continued to report inferior outcomes (OHS 36.5 vs 43, p=0.004). The functional outcome of asymptomatic patients was unaffected by revision surgery (pre-revision OHS 41, post-revision OHS 43, p=0.4). Linear regression analysis confirmed use of a cobalt-chrome (CoCr)-containing bearing surface (MoM or metal-on- polyethylene) at revision and increasing BMI were predictive of poor functional outcome (R. 2. 0.032, p=0.0224 and R. 2. 0.039, p=0.015 respectively). Pre- and post-revision serum metal ions and pre-revision MRI findings were not predictive of outcome. The overall complication rate was 36% (n=65) with a re-revision rate of 6.7%. The most common complication was ongoing adverse reaction to metal debris (ARMD, defined as positive post-revision MRI) in 21.1%. The incidence of ongoing ARMD was not significantly different between those with CoCr reimplanted and those without (p=0.12). Conclusions. To our knowledge, our study represents the largest single-centre consecutive series of revision THRs from MoM bearings in the literature. Symptomatic patients experience the greatest functional benefit from revision surgery but do not regain the same level of function as patients who were asymptomatic prior to revision. The re-implantation of CoCr as a primary bearing surface and increasing BMI was associated with poorer functional outcome

Background. The posterior slope of the tibial component in total knee arthroplasty (TKA) has been reported to vary widely even with computer assisted surgery. In the present study, we analyzed the influence of posterior tibial slope on one-year postoperative clinical outcome after posterior-stabilized (PS) -TKA to find out the optimal posterior slope of tibial component. Materials and Method. Seventy-three patients with varus type osteoarthritic (OA) knees underwent PS-TKA (Persona PS. R. ) were involved in this study. The mean age was 76.6 years old and preoperative HKA angle was 14.3 degrees in varus. Tibial bone cut was performed using standard extra-medullary guide with 7 degrees of posterior slope. The tibial slopes were radiographically measured by post-operative lateral radiograph with posterior inclination in plus value. The angle between the perpendicular line of the proximal fibular shaft axis and the line drawn along the superior margin of the proximal tibia represented the tibial slope angle. We assessed one-year postoperative clinical outcomes including active range of motion (ROM), patient satisfaction and symptoms scores using 2011 Knee Society Score (2011 KSS). The influences of posterior tibial slope on one-year postoperative parameters were analyzed using simple linear regression analysis (p<0.05). Results. The average posterior tibial slope was 6.4 ± 2.0 °. The average active ROM were −2.4 ± 6.6 ° in extension and 113.5± 12.6 ° in flexion. The mean one-year postoperative patient satisfaction and symptom scores were 29.3 ± 6.4 and 19.6 ± 3.9 points respectively. The active knee extension, satisfaction and symptom scores were significantly negatively correlated to the posterior tibial slope (r = −0.25, −0.31, −0.23). Discussion. In the present study, we have found significant influence of the posterior tibial slope on the one-year postoperative clinical outcomes in PS-TKA. The higher posterior slope would induce flexion contracture and deteriorate patient satisfaction and symptom. We had reported that the higher tibial posterior slope increased flexion gap and the component gap change during knee flexion in PS-TKA. Furthermore, another study reported that increase of the posterior tibia slope reduced the tension in the collateral ligaments and resulted in the knee laxity at flexion. The excessive posterior slope of tibial component would result in flexion instability, and adversely affected the clinical results including patient satisfaction and symptom. Conclusion. In the PS-TKA for varus type OA knees, excessive tibial posterior slope was found to adversely affect one-year postoperative knee extension and clinical outcome including patient satisfaction and symptom. Surgeons should aware of the importance of tibial slope on one-year postoperative clinical results and pay more attentions to the posterior tibial slope angle not to be excessive

Complications involving the patellofemoral joint are a source of anterior knee pain, instability, and dysfunction following total knee arthroplasty. “Overstuffing” the patello-femoral joint refers to an increase in the thickness of the patellofemoral joint after a total knee replacement compared to the preoperative thickness. While biomechanical studies have indicated that overstuffing the patellofemoral joint may lead to adverse clinical outcomes, limited clinical evidence exists to support this notion. The purpose of this study is to evaluate the effect of changing the thickness of the patellafemoral joint on functional outcomes following total knee arthroplasty. Our institutional arthroplasty database was used to identify 1347 patients who underwent a primary total knee arthroplasty between 2006 and 2012 with the same component design. Standard preoperative and postoperative anteroposterior, lateral, and skyline radiographs were collected and measured for patello-femoral overstuffing. These measurements included anterior patellar displacement, anterior femoral offset, and anteroposterior femoral size. These measurements were correlated with patient outcome data using WOMAC, KSS scores, and postoperative range of motion. Multiple linear regression analysis was used to assess the association between stuffing and functional outcomes. A total of 1031 patients who underwent total knee arthroplasty were included. Increased anterior patellar displacement, a measure of patellofemoral joint thickness, was associated with decreased WOMAC scores (p=0.02). Anterior femoral offset (p=0.210) and anteroposterior femoral size (p=0.091) were not significantly associated with patient functional outcomes. Postoperative range of motion (ROM) was not associated with patellofemoral stuffing (p=0.190). The current study demonstrated that functional outcomes are adversely affected by patellofemoral overstuffing. Based on these results, caution is encouraged against increasing the thickness of the patellofemoral joint, particularly on the patellar side of the joint

Background. In recent literatures, medial instability after TKA was reported to deteriorate early postoperative pain relief and have negative effects on functional outcome. Furthermore, lateral laxity of the knee is physiological, necessary for medial pivot knee kinematics, and important for postoperative knee flexion angle after cruciate-retaining total knee arthroplasty (CR-TKA). However, the influences of knee stability and laxity on postoperative patient satisfaction after CR-TKA are not clearly described. We hypothesized that postoperative knee stability and ligament balance affected patient satisfaction after CR-TKA. In this study, we investigated the effect of early postoperative ligament balance at extension on one-year postoperative patient satisfaction and ambulatory function in CR-TKAs. Materials & Methods. Sixty patients with varus osteoarthritis (OA) of the knee underwent CR-TKAs were included in this study. The mean age was 73.6 years old. Preoperative average varus deformity (HKA angle) was 12.5 degrees with long leg standing radiographs. The knee stability and laxity at extension were assessed by stress radiographies; varus-valgus stress X-ray at one-month after operation. We measured joint separation distance (mm) at medial compartment with valgus stress as medial joint opening (MJO), and distance at lateral compartment with varus stress as lateral joint opening (LJO) at knee extension position. To analyze ligament balance; relative lateral laxity comparing to the medial, varus angle was calculated. New Knee Society Score (NKSS) was used to evaluate the patient satisfaction at one-year after TKA. We measured basic ambulatory functions using 3m timed up and go test (TUG) at one-year after surgery. The influences of stability and laxity parameters (MJO, LJO and varus angle at extension) on one-year patient satisfaction and ambulatory function (TUG) was analyzed using single linear regression analysis (p<0.01). Results. MJOs at knee extension one-month after TKA negatively correlated to patient satisfaction (r=−0.37, p<0.01) and positively correlated to TUG time (r=0.38, p<0.01). LJOs at knee extension had no statistically significant correlations to patient satisfaction and TUG. The extension varus angle had significant positive correlation with patient satisfaction (r=0.40, p<0.01). Discussions. In our study, we have found significant correlations of the early postoperative MJOs at extension to postoperative patient satisfaction and TUG one-year after CR-TKA. Our results suggested that early postoperative medial knee stabilities at extension were important for one-year postoperative patient satisfaction and ambulatory function in CR-TKA. Other interest finding was that postoperative patient satisfaction was positively correlated with extension varus angle. This finding suggested that varus ligament balance; relative lateral laxity to medial stability, was beneficial for postoperative patient satisfaction after CR-TKA. Intra-operative soft tissue balance had been reported to significantly affect postoperative knee stabilities. Therefore, with our findings, surgeons might be better to manage intra-operative soft tissue balance to preserve medial stability at extension with permitting lateral laxity, which would enhance patient satisfaction and ambulatory function after CR-TKA for varus type OA knee. Conclusion. Early postoperative medial knee stability and relative lateral laxity would be beneficial for patient satisfaction and function after CR-TKA

Aim. Negative pressure wound treatment (NPWT) has been widely adopted in the management of septic wound complications or prophylactically after large surgeries. Recent publications have indicated the necessity of further investigations to support the use of NPWT with more evidences. Therefore, the purpose of this pilot-study was to investigate the efficacy of VAC-assisted dressing systems in the treatment of septic trauma cases. Method. We analysed data of 16 retrospective cases following traumas and septic soft tissue surgeries around the hip and knee. The collected data consisted of bacterial cultures, inflammatory markers (WBC, CRP/HCRP) and body temperature, taken periodically during treatment. Also recorded were the time periods the vacuum pump was used during treatment. To increase the number of measurements and to facilitate subsequent data analysis, the measurements were interpolated to regularly sampled curves with a sampling rate of one day. We used cross-plots and linear regression analysis to investigate trends in the data: 1) while the vacuum pump was switched on and 2) while it was switched off. Results. The analysis shows that the average WBC and CRP/HCRP values decline in the first days after initiation of the VAC treatment. WBC values decline in the first four days of VAC treatment (linear regression, R. 2. =0.960). CRP/HCRP values decline in the first thirteen days (linear regression, R. 2. =0.952). No meaningful trends were observed in body temperature measurements. Importantly, there is a trend for an increase of WBC and CRP/HCRP, following the 4. th. and 14. th. days, respectively. These findings suggest that the prolonged use of VAC treatment may result in secondary relapses. Conclusions. Our results indicate a marked decrease of inflammatory markers during the first two weeks, confirming the efficacy of NPWT in the management of septic wounds after traumas. Importantly, our analyses also show a periodic relapse with the prolonged use of NPWT. However, further studies are needed with a larger, standardized population to confirm these findings

Background. Intravenous and topical tranexamic acid (TXA) has become increasingly popular in total joint arthroplasty to decrease perioperative blood loss. In direct comparison, the outcomes and risks of either modality have been found to be equivalent. In addition, current literature has also demonstrated that topical TXA is safe and effective in the healthy population. To our knowledge, there is a scarcity of studies demonstrating the safety of topical TXA in high risk patient populations undergoing total joint arthroplasty or revision joint arthroplasty. The purpose of this study is to determine the safety of topical TXA in patients undergoing total or revision arthroplasty that are also on chronic anticoagulant or anti-platelet therapy. Methods. We performeded a retrospective review of patients undergoing primary and revision total hip or knee arthroplasties that received topical TXA (3g/100mL NS) from November 2012 to March 2015. All patients, regardless of co-morbidities, were included in the study population. Patients were divided into 3 groups:. Group 1: Patients without any antiplatelet or anticoagulant therapy within 90 days of surgery. Group 2: Patients receiving antiplatelet therapy (Aspirin and/or Plavix) within 90 days of surgery. Group 3: Patients receiving anti-coagulant therapy within 90 days of surgery (low molecular weight heparin, unfractionated heparin, warfarin, dabigatran, rivaroxaban, apixaban). Chart review analyzing ICD-9 and ICD-10 coding was then utilized to establish any peri-operative complications within the 30 day post-operative period in all groups. Complications amongst the groups were evaluated via chi-squared testing as well as multivariate linear regression. Review of current literature and CMS protocols were used to establish reportable peri-operative complications. Wound infections, thromboembolic events and vascular complications such as myocardial infarction, pulmonary embolism, deep venous thrombosis, stroke, aortic dissection were included. Results. During the study period, a total 1471 total joint arthroplasties were performed on 1324 patients (88.7% knee arthroplasty, 11.3% hip arthroplasty). Group 1 included 1033 patients who were not on any prior anti-platelet or anticoagulant therapy. Group 2 included 254 patients receiving chronic antiplatelet therapy 90 days prior to surgery. Group 3 included 184 patients receiving chronic anticoagulant therapy 90 days prior to surgery. No statistically significant differences were found between the groups for any of the included peri-operative complications. The most common complication occurring amongst all the groups was superficial wound infection, which occurred in a total of 60 (4.1%) patients in contrast to 18 (1.2%) patients who sustained an acute deep peri-prosthetic infection. Twenty (1.4%) patients sustained an ultrasound proven deep vein thrombosis, with the highest prevalence occurring in those patients receiving no anticoagulation prior to surgery (15/20, 75%), however this was not statistically significant following linear regression analysis. Conclusions. To our knowledge, this is the first study that demonstrates that topical tranexamic acid is safe to use in so-called high risk patients who are being treated prior to surgery with anti-platelet or anti-coagulation therapy

Aims

Disorders of bone integrity carry a high global disease burden, frequently requiring intervention, but there is a paucity of methods capable of noninvasive real-time assessment. Here we show that miniaturized handheld near-infrared spectroscopy (NIRS) scans, operated via a smartphone, can assess structural human bone properties in under three seconds.

Objective. As the aging society progresses rapidly in Japan, the number of elderly patients underwent TKA is increasing. These elderly patients do not expect to do sports, but regain independency in the activity of daily living. Therefore, we measured basic ambulatory function quantitatively using 3m timed up and go (TUG) test. We clinically experienced patient with medially unstable knee after TKA was more likely to result in the unsatisfactory outcome. We hypothesized that post-operative knee stability influenced ambulatory function recovery after TKA. In this study, we evaluated ambulatory function and knee stability quantitatively, and analyzed the effect of knee stability on the ambulatory function recovery after TKA. Materials & Methods. Seventy nine patients with varus type osteoarthritic knees underwent TKA were subjected to this study. The mean age of surgery was 72.4 years old. Preoperative standing coronal deformity was 9.6 degrees in varus. TUG test results in less duration with faster ambulatory function. TUG (seconds) was measured at 3 time periods; pre-operatively, at hospital discharge and 1year after surgery. To standardize TUG recovery time during 1 year after TKA, we defined TUG recovery rate as the percentage of recovery time to the pre-operative TUG as shown in the following equation. TUG recovery rate (%) = (TUG pre-op –TUG 1y po) / TUG pre-op ×100. We also evaluated the knee stability at hospital discharge and 1year after surgery. The knee stability at extension and flexion were assessed by varus and valgus stress radiography using Telos (10kg) and stress epicondylar view with 1.5kg weight at the ankle respectively. Image analyzing software was used to measure joint separation distance (mm) at medial as medial joint opening (MJO) and at lateral as lateral joint opening (LJO) at both knee extension and flexion. (Fig.1). The sequential change of TUG was analyzed using repeated measures ANOVA (p<0.05). The influence of joint opening distances (MJO and LJO at extension and flexion) on TUG 1y po and TUG recovery rate were analyzed using simple linear regression analysis (p<0.05). Results. The mean TUGs were 13.4, 13.7 and 10.8 seconds pre-operatively, at hospital discharge and 1 year after TKA respectively. Significant decrease was found at 1 year after surgery. TUG pre-op did not show significant correlation to any joint openings. TUG 1y po was positively correlated with both flexion and extension MJO at hospital discharge. (Fig.2) TUG recovery rate negatively correlated to flexion-MJO at hospital discharge. (Fig.3). Discussions. The most interesting findings in the present study were that both flexion and extension MJO at hospital discharge were positively correlated with TUG 1y po and negatively correlated with TUG recovery rate. This indicated that early post-operative medial stability played an important role in the recovery of ambulatory function. The early post-operative medial instability would cause pain and deteriorate functional recovery after surgery. There is some disagreement regarding the importance of pursuing the perfect ligament balance, which would be more likely to result in medial instability. Consequently, surgeons should prioritize medial stability for better ambulatory functional recovery after TKA

Introduction. In cases of unilateral clubfoot, the leg and foot is visually smaller than the opposite, uninvolved side. Parents want to know how much smaller the leg and foot will be. The purpose of this study was to answer this question and compare the results of children treated with a posterior medial release (PMR) with those treated with the Ponseti method (PM). Methods. This is a prospective, longitudinal study of calf circumference and foot length. We measured the calf circumference with a tape measure at the visually maximum girth of the uninvolved side and at the symmetrical position of the involved side. We measured each foot length from the tip of the hallux to the end of the heel. We recorded the measurements at each follow-up visit in a database and analysed the data using linear regression analysis. Results. We followed 93 children (65 PMR, 28 PM) for a mean of 68 months (SD 55, range 6-252) The ratio men/women was 53/40. Mean percent calf size difference was 9.83% (95%CL 8.74-10.92%). Mean percent foot size difference was 8.70% (95%CL 7.54-9.87%). From the numbers available, no differences between the two procedures are evident. Conclusion. Children with a unilateral clubfoot have c10% smaller calf circumference and foot length as compared to the uninvolved side. We found no differences between children treated with PMR or PM, implying the smaller size is intrinsic to the condition and not due to type of treatment

Introduction. Appropriate osteotomy alignment and soft tissue balance are essential for the success of total knee arthroplasty (TKA). The management of soft tissue balance still remains difficult and it is left much to the surgeon's subjective feel and experience. We developed an offset type tensor system for TKA. This device enables objective soft tissue balance measurement with more physiological joint conditions with femoral trial component in place and patello-femoral (PF) joint reduced. We have reported femoral component placement decreased extension gap. The purpose of the present study was to analyze the influence of femoral component size selection on the decrease of extension gap in posterior-stabilized (PS) TKA. Material & Method. 120 varus type osteoarthritic knees implanted with PS TKAs (NexGen LPS flex: Zimmer) were subjected to this study. All TKAs were performed using measured resection technique with anterior reference. The femoral component size was evaluated intra-operatively using conventional femoral sizing jig. The selected femoral component size was expressed by the antero-posterior (AP) size increase (mm) comparing to that of original femoral condyles. Gap measurements were performed using a newly developed offset type tensor device applying 40lbs (178N) of joint distraction force. Firstly, conventional osteotomy gaps (mm) were measured at extension and flexion. Secondary, component gaps (mm) after femoral trial placement with PF joint reduced were evaluated at 0° and 90° of knee flexion. To compare conventional osteotomy gaps and component gaps, estimated extension and flexion gaps were calculated by subtracting the femoral component thickness at extension (9mm) and flexion (11mm) from conventional osteotomy gaps respectively. The decrease of gap at extension and flexion were calculated with estimated gaps subtracted by component gaps. The simple linear regression analysis was used to evaluate the influence of selected femoral component size on the decrease of gap after femoral component placement. Results. The mean extension and flexion conventional osteotomy gaps were 25.7 and 28.2 mm, and estimated gaps were 16.7, 17.2 mm respectively. The component gaps were 11.1, 16.9 mm at 0° and 90° of knee flexion respectively. Extension joint gap was significantly decreased as much as 5.6mm after femoral component placement, but flexion gap showed no significant differences. Selected femoral component size showed a positive correlation to the decrease of gap after femoral component placement (Fig 1). Discussion & Conclusion. This result indicates that AP femoral component size variation affects not only flexion gap but also extension gap in PS TKA. With the larger femoral component size selected, the more protrusion of posterior condyles would increase the more tension on the posterior structures and resulted in the more decrease of joint gap after femoral component placement at full extension. This mechanism might play a physiological role on the prevention of knee hyper-extension, and would be affected by flexion contracture. Accordingly, we conclude that the surgeon should aware of the effect of femoral component placement on the gap control, and femoral component size selection affects not only flexion gap but also extension gap after femoral component placement in PS TKA

Proximal femoral deformity is common in children with cerebral palsy (CP), contributing to hip instability and ambulation difficulties. This population-based cohort study investigates the prevalence and significance of these deformities in relation to Gross Motor Function Classification System (GMFCS) level. Children with a confirmed diagnosis of CP born within a three-year period were identified from a statewide register. Motor type, topographical distribution and GMFCS level were obtained from clinical notes. Neck Shaft Angle (NSA) and Migration Percentage (MP) were measured from an anteroposterior pelvis x-ray with the hips internally rotated. Measurement of FNA was by the Trochanteric Palpation Test (TPAT) or during fluoroscopic screening of the hip with a guide wire in the centre of the femoral neck. Linear regression analysis was performed for FNA, NSA and MP according to GMFCS level. 292 children were eligible. FNA was increased in all GMFCS levels. The lowest measurements were at GMFCS levels I and II p<0.001. GMFCS levels III, IV, and V were uniformly high p<0.001. Neck shaft angle increased sequentially from GMFCS levels I to V (p<0.001). This study confirms a very high prevalence of increased FNA in children with CP in all GMFCS levels. In contrast, NSA and MP progressed step-wise with GMFCS level. We propose that increased FNA in children with CP represents failure to remodel normal fetal alignment because of delay in ambulation and muscle imbalance across the hip joint. In contrast, coxa valga is an acquired deformity and is largely related to lack of weight bearing and functional ambulation. The high prevalence of both deformities at GMFCS levels IV and V explain the high rate of displacement in these hips and the need for proximal femoral realignment surgery in the prevention and management of hip displacement

Aim. To assess the efficacy and ease of use of the Oxford Knee Score (OKS) in soft tissue knee pathology. Method. In a prospective study, we compared the OKS against the International Knee Documentation Committee 2000 (IKDC) and the Lysholm Scores (Lys). We also assessed the OKS with retrograde (Reversed OKS: 48=worst symptoms, 0=asymptomatic) and antegrade (as currently used in Oxford) numbering. All patients completed 3 questionnaires (OKS, Lys, and IKDC, or RevOKS, Lys, and IKDC) stating which was the simplest from their perspective. We recruited 93 patients from the orthopaedic and physiotherapy clinics. All patients between the ages of 15 and 45 with soft tissue knee derangements, such as ligamentous, and meniscal injuries were included. Exclusions were made in patients with degenerative and/or inflammatory arthritidis. Patients who had sustained bony injuries or underwent bony surgery were also excluded. Results. The distribution of the soft tissue injuries was: Meniscal tears (35%), anterior cruciate ligament injuries (23%), anterior knee pain (22%), other injuries (12%), and collateral ligament damage (8%). Linear regression analysis revealed no significant difference between all 3 scores (R squared=0.7823, P<0.0001). The OKS correlated best with the IKDC (r=0.7483), but less so with the Lys (r=0.3278). The reversed OKS did not correlate as well (R squared= 0.2603) with either the IKDC (r= -0.2978) or the Lys (r=-0.2586). ANOVA showed the OKS to be significantly easier than Lys to complete (p<0.0001), but not significantly easier than IKDC (p>0.05). Conclusion. The OKS is patient friendly and reliable in assessing soft tissue knee injury. This is particularly useful if the OKS is already in use within a department for assessment of degenerative disease. The Oxford Knee score should be used in an antegrade fashion (with a score of 48/48 corresponding to maximum symptoms) to give the best results in objective assessment

Background and Objective. Patients undergoing hip fracture surgery have a high peri-operative mortality rate. We performed a retrospective study to ascertain if there is any relation between postoperative haemoglobin (Hb) decrease and cardiac related events following the surgery. Methodology. We carried out a retrospective study in this University Hospital's trauma unit. All patients operated for fracture neck of femur (hemiarthroplasty and DHS – Dynamic Hip Screw) between July 2006 and August 2008 were included in the study. Electronic records from the trauma unit, pathology portal, operating theatre and blood bank were obtained to identify the pre-operative and post-operative Hb levels, amount of blood transfused and Troponin T (TnT) level. Results. A total of 632 patients were operated for fracture neck of femur surgery during the study period of which 616 had complete perioperative blood results (DHS: 341; 80 male and 261 females and Hemiarthroplasty: 275; 68 male and 207 females). 60 patients had TnT levels performed within 10 days of the operation, thus suggesting possible cardiac related symptoms. Of these, 25 patients had a raised TnT (= 0.03). 24 (96%) of these patients had a post-operative Hb decrease compared with 550/591 (93%) patients without TnT (mean 2.3, range 0.1-5.6 g/dl compared with a mean of 2.4 and a range of 0-7 g/dl). Scatter diagram illustrated a positive correlation between post-operative Hb drop and TnT rise. Linear regression analysis concluded that a post-operative Hb drop is significantly correlated to TnT rise at the 10% level (p = 0.064). Conclusions. Post-operative Hb decline correlates with a raised TnT. As a standard protocol, post-operative bloods including Hb are performed the day after surgery. Given the correlation demonstrated, we recommend Hb levels to be analysed on day of surgery, to effectively manage low Hb levels before cardiac symptoms can develop

It has been proposed that higher knee adduction moments and associated malalignment in subjects with severe medial knee joint osteoarthritis (OA) is due to anatomical deformities as a result of OA [1, 2]. The emergence of patient-matched implants should allow for correction of any existing malalignment. Currently the plans for such surgeries are often based on three dimensional supine computed tomography (CT) scans or magnetic resonance imaging (MRI), which may not be representative of malalignment during functional loading. We investigated differences in frontal plane alignment in control subjects and subjects with severe knee joint OA who had undergone both supine imaging and gait analysis. Fifteen subjects with severe knee OA, affecting either the medial or lateral compartment, and 18 control subjects were selected from a database established as part of a larger study. All subjects had undergone gait analysis using the Vicon motion capture system. OA subjects had undergone routine CT scans and were scheduled for knee joint replacement surgery. Control subjects had no known musculoskeletal conditions and had undergone MRI imaging of hip, knee and ankle joints. Frontal plane knee joint angles were measured from supine imaging (supine) and from motion capture during standing (static) and during gait at the first peak ground reaction force (gait). OA subjects had a significantly higher BMI (p < 0.01) and different gender composition (13 males and 2 females vs 4 males and 5 females; p = 0.03) compared with controls. Multiple linear regression analysis indicated no significant confounding effect of these differences on frontal plane angles measured in supine, static or gait conditions. For both OA and healthy subjects, frontal plane knee angles were significantly higher during gait compared with supine (p = 0.03 and 0.02, respectively). There were also significant differences in knee alignment between OA and healthy subjects for supine and static (p < 0.05) but not for gait, although this was approaching significance (p = 0.052). Overall there seemed to be higher variation in alignment in the OA subjects (Fig. 1). The significantly higher frontal plane knee joint angles measured in both control and OA subjects during gait compared with supine imaging indicate that functional alignment should be taken into consideration when planning patient-specific surgeries. Higher variation in OA patients may be due to alterations in gait patterns due to pain or degree of wear in their osteoarthritic joints, and requires further investigation. In addition, methodological considerations should be taken when comparing alignment from measurements taken with imaging and motion capture to avoid systematic errors in the data. In conclusion, we believe that both supine and loadbearing imaging are insufficient to gain a full representation of functional alignment, and analysis of functional alignment should be routinely performed for optimal surgical planning

Introduction. Several studies have described the relationship between the joint line and bony landmarks around the knee. However, high inter-patient variation makes these absolute values difficult in use. This study was set up to validate the previously described distances and ratios on calibrated full limb standing X-rays and to investigate the accuracy and reliability of these ratios as a tool for joint line reconstruction. Methods:. One hundred calibrated full-leg standing radiographs obtained from healthy volunteers were reviewed (fig 1). Distances from the medial epicondyle, the lateral epicondyle, the adductor tubercle, the fibular head and the proximal center of the knee (CJD) to the virtual prosthetic joint line were determined (fig 3). This prosthetic joint line was created by introducing a virtual distal femoral cutting block with a valgus angle of 6° on the full-leg radiographs. The adductor ratio was defined as the distance from adductor tubercle to the joint line divided by the femoral width. The correlation with the femoral width, the CJD and the limb alignment was analysed using linear regression analysis. The accuracy and reliability of the use of the ratio of the distance of the adductor tubercle, the medial epicondyle and the CJD relative to the femoral width to reconstruct the joint line was calculated. Results:. The average distance to the joint line from the medial epicondyle, the lateral epicondyle, the adductor tubercle and the fibular head was 28 mm (SD 2.97), 27 mm (SD 2.67), 44 mm (SD 4,27) and 15 mm (SD 3.69) respectively. The distance from the adductor tubercle (R = 0,82) and the CJD (R = 0,96) to the joint line showed a strong and significant linear correlation with the femoral width. The medial epicondyle, the lateral epicondyle and the fibular head showed less strong correlations. There was no significant correlation with the limb alignment. The adductor ratio was found to be 0.52 (SD 0.027) with only small inter-individual variation. The use of the adductor ratio reconstructed the joint line within 4 mm of its original level in 92% of the cases. Discussion. The absolute distances and ratios for determining joint line position as previously described, were confirmed on calibrated full-limb standing radiographs. Recently, the adductor tubercle has been described as a reliable landmark for determining joint line position. As a rule of thumb, the femoral width as measured on the preoperative radiograph or intra-operative, is divided by 2. Intra-operative, the distance from the adductor tubercle to the distal cutting block that has been inserted with a 6° distal cutting angle, is adjusted to equal the calculated value. Fixation of the cutting block at this level will automatically reconstruct the joint line at its original level (fig 2). Modern instrumentation techniques will allow you to immediately select the appropriate size distal femoral augment to reconstruct this joint level. Conclusion. The adductor ratio was found to be the most useful and accurate tool to restore the joint line to its original level in revision TKA

Introduction:. Computer-assisted surgery (CAS) aims to improve component positioning and mechanical alignment in Total Knee Arthroplasty (TKA). Robotic cutting-guides have been integrated into CAS systems with the intent to improve bone-cutting precision and reduce navigation time by precisely automating the placement of the cutting-guide. The objectives of this study were to compare the intra-operative efficiency and accuracy of a robotic-assisted TKA procedure to a conventional computer-assisted TKA procedure where fixed sequential cutting-blocks are navigated free-hand. Methods:. This was a retrospective study comparing two distinct cohorts: the control group consisted of patients undergoing TKA with conventional CAS (Stryker Universal Knee Navigation v3.1, Stryker Orthopaedics, MI) from May 2006 to September 2007; the study group consisted of patients undergoing TKA with a robotic cutting-guide (Apex Robotic Technology, ART, OMNIlife Science, MA) from October 2010 to May 2012. Exclusion of patients with preexisting hardware in the joint or an absence of navigation data resulted in a total of 29 patients in the control group and 52 patients in the study group. Both groups were similar with respect to BMI, age, gender, and pre-operative alignment. All patients were operated on by a single surgeon at a single institution. The navigation log files were analyzed to determine the total navigation time for each case, which was defined as the time from the start of the acquisition of the hip center to the end of the final alignment analysis for both systems. The intraoperative final mechanical axis was also recorded. The tourniquet time (time of inflation prior to incision to deflation immediately after cement hardening) and hospitalization length were compared. Linear regression analysis was performed using R statistical software v2.12.1. Results:. Navigation times were on average 9.0 minutes shorter in the study group compared to the control group (95% CI: [4.0, 14.1], p = 0.0006). Average absolute intraoperative alignment was 0.5 degrees closer to neutral in the robotic group compared to the conventional CAS group (95% CI: [0.08, 0.95], p = 0.020). Tourniquet time was not significantly different between the two systems (0.2 min, 95% CI [−5.4, 5.9], p = 0.926). Patients in the study group were discharged 0.6 days earlier than patients in the control group (95% CI: [0.1, 1.1], p = 0.0122). Discussions:. Our results suggest that use of a robotic cutting-guide can decrease the time taken to navigate a TKA procedure in comparison to conventional free-hand navigation of multiple fixed cutting blocks, which is supported by previous studies [1]. However, this time savings did not translate into a reduction in the tourniquet time. We believe this may be due in part to the two different types of bone cement that were used during the distinct study periods, where the hardening time for the cement in the study group was estimated to be approximately 5 minutes longer. Conclusions:. In one surgeon's hands, use of a robotic cutting-guide decreased navigation time, improved intraoperative final alignment, and decreased hospitalization length when compared to conventional computer-assisted navigation in TKA

[Introduction]. Rapid increase of aged population has been one of major issue affecting national health care plan in Japan. In 2006, Japanese Orthopaedic Association indicated a new clinical entity of musculoskeletal ambulation disorder symptom complex (MADS) to define the higher risk of fall and ambulatory disability in the elderly population caused by musculoskeletal disorders. Osteoarthritis of the knee is one of major cause of MADS. The number of patients with MADS underwent total knee arthroplasty (TKA) had been increased in Japan, and also expected to increase worldwide in the near future. The effectiveness of TKA for the patient with MADS would be a key issue for the patient satisfaction in TKA. In the present study, we analyzed the influence of pre-operative factors on the ambulatory functions in the patients of primary TKA. [Material & Method]. 132 patients with osteoarthritic knees implanted with posterior-stabilized (PS) TKAs were subjected to this study. There were 113 female and 19 male patients. The mean age of the patients was 73.6 years (range, 59 to 87 years). Patients were pre-operatively subjected to 2 functional performance tests which were essential tests for MADS diagnosis. Firstly, 3 meter timed up and go test (TUG) was used to evaluate ambulation ability. Secondary one leg standing time (ST) with open eyes was measured with both operated and non-operated leg to assess balancing ability. MADS was diagnosed if TUG and ST were not less than 11 seconds and/or less than 15 seconds respectively. The influence of each pre-operative factor was evaluated simple linear regression analysis (p < 0.05). Pre-operative factors consisted of age, sex, weight, height, BMI, standing femoro-tibial angle (FTA) and active knee range of motion. [Results]. Pre-operatively, 74% of the patients was diagnosed as MADS, with the results of 64, 74 and 64% of the patient matched to the MADS criteria with the evaluation of TUG and ST with operated and non-operated leg respectively (Fig 1). Firstly, pre-operative TUG was found to be negatively correlated to the weight (R = −0.25), ST with non-operated leg (R = −0.24) and active knee flexion angle (R = −0.28, Fig 2). Secondary, ST with operated leg was significantly affected by age (R = −0.32), standing FTA (R = −0.38) and ST with non-operated leg (R = 0.66, Fig 3). [Discussion & Conclusion]. As much as 74% of our patients was suffered from MADS before primary TKA. Majority of patient had both ambulatory and balancing disability with higher risk of fall and ambulatory dysfunction. We found ST with non-operated leg significantly affected both TUG representing ambulatory function and ST representing balancing function. This means the contra-lateral lower extremity function would play an important role on the pre-operative functional ability in the patient of TKA. Furthermore, we found pre-operatively that active knee flexion influenced ambulatory function, and coronal knee deformity deteriorated balancing ability. Then we should evaluate these pre-operative factors in analyzing the effectiveness of TKA on the functional recovery in the elderly patient underwent primary TKA