Aims. Treatment of Weber B ankle fractures that are stable on weightbearing radiographs but unstable on concomitant stress tests (classified SER4a) is controversial. Recent studies indicate that these fractures should be treated nonoperatively, but no studies have compared alternative nonoperative options. This study aims to evaluate patient-reported outcomes and the safety of fracture treatment using functional orthosis versus cast immobilization. Methods. A total of 110 patients with Weber B/SER4a ankle fractures will be randomized (1:1 ratio) to receive six weeks of functional orthosis treatment or cast immobilization with a two-year follow-up. The primary outcome is patient-reported ankle function and symptoms measured by the Manchester-Oxford Foot and Ankle Questionnaire (MOxFQ); secondary outcomes include Olerud-Molander Ankle Score, radiological evaluation of ankle congruence in weightbearing and gravity stress tests, and rates of treatment-related adverse events. The Regional Committee for Medical and Health Research (approval number 277693) has granted ethical approval, and the study is funded by South-Eastern Norway Regional Health Authority (grant number 2023014). Discussion. Randomized controlled trials are needed to evaluate alternative nonoperative treatment options for Weber B/SER4a ankle fractures, as current clinical guidelines are based on biomechanical reasoning. The findings will be shared through publication in peer-reviewed journals and presentations at conferences. Cite this article: Bone Jt Open 2023;4(9):713–719

The work capacity of 26 women after a Chiari pelvic osteotomy for symptomatic unilateral subluxation of the hip was assessed using two simple exercise tests: the maximal walking speed during a 12-minute test and the time taken to climb stairs. A significant linear decline in walking speed occurred with increasing age, despite the operation, and only one patient over the age of 25 years was able to walk at a normal rate. Compared to the results in a control group of women of similar age the stair climbing time was increased in 54 per cent of the patients and showed a significant negative correlation with the maximal walking speed. Age-adjusted walking speed was closely associated with the degree of pain experienced but there was no relationship between observed function and conventional clinical assessment based on the range of movement and the radiographic appearances of the hip

In 30 elderly women awaiting hip arthroplasty on account of unilateral osteoarthritis of the hip, walking speed and oxygen consumption were measured during a 12-minute test and the power output was calculated from the stair climbing rate. The results were compared with those for a group of 30 normal women of similar age. An age-related decline in maximal walking speed was observed in both groups. After arthroplasty there was a significant increase in maximal walking speed, particularly among the more disabled patients, with the major gain occurring by three months and a further slight increase by six months. Oxygen consumption returned towards normal values, and both stride length and cadence increased by a comparable degree. Mean power output during stair climbing doubled, and both before and after arthroplasty bore a linear relationship to the maximal walking speed.

We prospectively assessed the diagnostic accuracy of the gravity stress test and clinical findings to evaluate the stability of the ankle mortise in patients with supination–external rotation-type fractures of the lateral malleolus without widening of the medial clear space. The cohort included 79 patients with a mean age of 44 years (16 to 82). Two surgeons assessed medial tenderness, swelling and ecchymosis and performed the external rotation (ER) stress test (a reference standard). A diagnostic radiographer performed the gravity stress test. For the gravity stress test, the positive likelihood ratio (LR) was 5.80 with a 95% confidence interval (CI) of 2.75 to 12.27, and the negative LR was 0.15 (95% CI 0.07 to 0.35), suggesting a moderate change from the pre-test probability. Medial tenderness, both alone and in combination with swelling and/or ecchymosis, indicated a small change (positive LR, 2.74 to 3.25; negative LR, 0.38 to 0.47), whereas swelling and ecchymosis indicated only minimal changes (positive LR, 1.41 to 1.65; negative LR, 0.38 to 0.47). . In conclusion, when gravity stress test results are in agreement with clinical findings, the result is likely to predict stability of the ankle mortise with an accuracy equivalent to ER stress test results. When clinical examination suggests a medial-side injury, however, the gravity stress test may give a false negative result. Cite this article: Bone Joint J 2015; 97-B:1126–31

Abstract. Background. Multi-ligament knee injury is a rare but severe injury. Treatment strategies are challenging for most orthopedic surgeons & optimal treatment remains controversial. The purpose of our study was to assess clinico-radiological and functional outcomes after surgical management of multi-ligament knee injuries & to determine factors that could predict outcome of surgery. Materials And Method. It is a prospective observational study of 30 consecutive patients of Multi-ligament knee injury conducted between 2018–2020. All patients were treated surgically with single-stage reconstruction of all injured ligaments and followed standardized postoperative rehabilitation protocol. All patients were evaluated for Clinical (VAS score, laxity stress test, muscle-strength, range of motion), Radiological (stress radiographs) & Functional (Lysholm score) outcomes three times-preoperatively, post-operative 3 & 12 months. Results. At final follow up mean VAS score was 0.86±0.77. The anteroposterior & valgus-varus stress test showed ligament laxity >10mm (GradeD) in 93.3% patient which improved to <3mm (normal, GradeA) in 90% patients. Most patients (83.3%) had preoperative-range <100° and muscle strength of MRC Grade-3 which improved to >120° and muscle strength of MRC grade-5 at final followup. Lysholm score was poor (<64) in all patients preoperatively and improved to good (85–94) in 73.3%, excellent (>95) in 20% & fair (65–84) in 6.6% patients. The stress radiographs showed stable results for anterior/posterior & varus/valgus stress. All patients returned to their previous work. Factors that could predict outcomes of surgery are age, timing of surgery, type of surgery & associated injury. Conclusion. Early complete single stage reconstruction can achieve good functional results with overall restoration of sports & working capacity. Positive predictive factors for good outcome are younger age, early surgery & appropriate rehabilitation

This study is designed to evaluate intra-operative stress testing on detection of syndesmosis injuries. We evaluated forty patients with ankle fractures requiring surgery. Their ankles were subjected to stress examinations after each stage of fixation. These were compared to the contralateral side. Biomechanical criteria were used to predict need for syndesmosis fixation. In 42% of the fractures, intra-operative fluoroscopy found an unpredicted syndesmosis injury. In 8% the syndesmosis was intact despite prediction. Medial malleolar fixation was not adequate for syndesmosis fixation as shown by stress testing. These findings may have implications for future diagnosis and treatment of syndesmosis injuries. This study is designed to evaluate the utility of intra-operative fluoroscopic stress testing in diagnosing tibio-fibular syndesmotic injuries. Forty skeletally mature patients with unilateral external rotation ankle fractures requiring open reduction and internal fixation were prospectively recruited. Intra-operatively the injured ankle was examined fluoroscopically using external rotation, valgus and anterior drawer stress tests, as well as static antero-posterior, mortise, and lateral ankle views. Stress testing was performed using a standardized force of 37.5 N. Stress testing was done after each stage of fixation (lateral, medial, and syndesmotic). The uninjured contralateral limb was examined as a control, and a 1 mm side to side difference was defined as a positive stress examination. Intra-operative fluoroscopy detected unpredicted syndesmotic injuries in 42 % of ankle injuries. In all cases, fixation of the medial malleolus did not restore syndesmotic stability. In 8 % of ankle injuries, a syndesmotic injury was predicted but stress testing revealed the syndesmosis intact. Intra-operative fluoroscopy is a more sensitive modality for detection of otherwise unpredicted syndesmotic injuries compared to criteria based upon static radiographs. Medial malleolar fixation did not add stability to syndesmotic injuries in this study. Injuries involving the distal tibio-fibular syndesmosis are difficult to detect. Previously, the decision to stabilize the syndesmosis in ankle fractures was based upon biomechanical criteria and static radiography. This and other recent studies challenge this, suggesting fluoroscopic stress testing is a better diagnostic method for these poorly tolerated injuries. Funding: Synthes Canada, Smith Nephew Richards Inc

As well as improved component alignment, recent publications have shown that navigation systems can assess knee kinematics and provide a quantitative measurement of soft tissue characteristics. In particular, navigation-based measures of varus and valgus stress angles have been used to define of the extent of soft-tissue release required at the time of the placement of the prosthesis. However, the extent to which such navigation-derived stress angles reflect the restraining properties of the collateral ligaments of the knee remain unknown. The aim of this cadaveric study was to investigate correlations between the structural properties of the collateral ligaments of the knee and stress angles measured with an optically-based navigation system. Nine fresh-frozen cadaveric knees (age 81 ± 11 years) were resected 10-cm proximal and distal to the knee joint and dissected to leave the menisci, cruciate ligaments, posterior joint capsule and collateral ligaments. The resected femoral and tibial were rigidly secured within a test system which replicated the lower limb and permitted kinematic registration of the knee using the standard workflow of a commercially available image free navigation system. Frontal plane knee alignment and varus-valgus stress angles in extension were acquired. The manual force required to produce varus-valgus stress angles during clinical testing was quantified with a dynamometer attached to the distal tibial segment. Following assessment of knee laxity, bone–ligament–bone specimens were prepared and mounted within a uniaxial materials testing machine. Following 10 preconditioning cycles specimens were extended to failure. Force and crosshead displacement were used to calculate principal structural properties of the ligaments including ultimate tensile strength and stiffness as well as the instantaneous stiffness at loads corresponding to those applied during varus-valgus stress testing. Differences in the structural properties of the collateral ligaments and the varus and valgus laxity of the knee were evaluated using paired t tests, while potential relationships were investigated with scatter plots and Pearson’s product moment correlations. There was no significant difference in the mean varus (4.3 ± 0.6°) and valgus laxity measured (4.3 ± 2.1°) for the nine knees or the corresponding distal force application required during stress testing (9.9 ± 2.5N and 11.1 ± 4.2N, respectively). Six of the nine knees had a larger varus stress angle compared to the valgus angle. There was no significant difference in the stiffness of the medial (63 ± 15 N/mm) and lateral (57 ± 13 N/mm) collateral ligaments during failure testing. The medial ligament, however, was approximately two fold stronger than its lateral counterpart (780 ± 214N verse 376 ± 104N, p< 0.001). While the laxity measures of the knee were independent of the ultimate tensile strength and stiffness of the collateral ligaments, there was a significant correlation between the force applied during stress testing and the instantaneous stiffness of the medial (r = 0.91, p = 0.001) and lateral (r = 0.68, p = 0.04) collateral ligaments. The findings of the current study suggest that computer-assisted measures of passive knee laxity are largely independent of the ultimate strength and stiffness of the collateral ligaments. The force applied during manual stress testing of the knee, however, was strongly correlated with the instantaneous stiffness of the collateral ligaments suggesting users may attend to the low-stress behaviour of the ligaments. Nonetheless the force applied during stress testing varied between knees, as did the resultant angular deviation. Therefore to make use of the quantified data given by navigation systems, further work to understand the relationships between applied force, resultant stress angles and clinical outcomes for knee arthroplasty is required

Clinical laxity tests are frequently used for assessing knee ligament injuries and for soft tissue balancing in total knee arthroplasty (TKA). Current routine methods are highly subjective with respect to examination technique, magnitude of clinician-applied load and assessment of joint displacement. Alignment measurements generated by computer-assisted technology have led to the development of quantitative TKA soft tissue balancing algorithms. However to make the algorithms applicable in practice requires the standardisation of several parameters: knee flexion angle should be maintained to minimise the potential positional variation in ligament restraining properties; hand positioning of the examining clinician should correspond to a measured lever arm, defined as the perpendicular distance of the applied force from the rotational knee centre; accurate measurement of force applied is required to calculate the moment applied to the knee joint; resultant displacement of the knee should be quantified. The primary aim of this study was to determine whether different clinicians could reliably assess coronal knee laxity with a standardised protocol that controlled these variables. Furthermore, a secondary question was to examine if the experience of the clinician makes a difference. We hypothesised that standardisation would result in a narrow range of laxity measurements obtained by different clinicians. Six consultant orthopaedic surgeons, six orthopaedic trainees and six physiotherapists were instructed to assess the coronal laxity of the right knee of a healthy volunteer. Points were marked over the femoral epicondyles and the malleoli to indicate hand positioning and give a constant moment arm. The non-invasive adaptation of a commercially available image-free navigation system enabled real-time measurement of coronal and sagittal mechanical femorotibial (MFT) angles. This has been previously validated to an accuracy of ±1°. Collateral knee laxity was defined as the amount of angular displacement during a stress manoeuvre. Participants were instructed to maintain the knee joint in 2° of flexion whilst performing a varus-valgus stress test using what they perceived as an acceptable load. They were blinded to the coronal MFT angle measurements. A hand-held force application device (FAD) was then employed to allow the clinicians to apply a moment of 18Nm. This level was based on previous work to determine a suitable subject tolerance limit. They were instructed to repeat the test using the device in the palm of their right hand and to apply the force until the visual display and an auditory alarm indicated that the target had been reached. The FAD was then removed and participants were asked to repeat the clinical varus-valgus stress test, but to try and apply the same amount of force as they had been doing with the device. Maximum MFT angular deviation was automatically recorded for each stress test and the maximum moment applied was recorded for each of the tests using the FAD. Means and standard deviations (SD) were used to compare different clinicians under the same conditions. Paired t-tests were used to measure the change in practice of groups of clinicians before, during and after use of the FAD for both varus and valgus stress tests. All three groups of clinicians initially produced measurements of valgus laxity with consistent mean values (1.5° for physiotherapists, 1.8° for consultants and 1.6° for trainees) and standard deviations (<1°). For varus, mean values were consistent (5.9° for physiotherapists, 5.0° for consultants and 5.4° for trainees) but standard deviations were larger (0.9° to 1.6°). When using the FAD, the standard deviations remained low for all groups for both varus and valgus laxity. Introducing the FAD overall produced a significantly greater angulation in valgus (2.4° compared to 1.6°, p<0.001) but not varus (p = 0.67) when compared to the initial examination. In attempting to reach the target moment of 18Nm, the mean ‘overshoot’ was 0.9Nm for both varus and valgus tests. Standard deviations for varus laxity were lower for all groups following use of the FAD. The consultants' performance remained consistent and valgus assessment remained consistent for all groups. The only statistically significant change in practice for a group before and after use of the FAD was for the trainees testing valgus, who may have been trained to push harder (p = 0.01). Standardising the applied moment indicated that usually a lower force is applied during valgus stress testing than varus. This was re-enforced by clinicians, one third of whom commented that they felt they had to push harder for valgus than varus, despite the FAD target being the same. We have successfully standardised the manual technique of coronal knee laxity assessment by controlling the subjective variables. The results support the hypothesis of producing a narrow range of laxity measurements but with valgus laxity appearing more consistent than varus. The incorporation of a FAD into assessment of coronal knee laxity did not affect the clinicians' ability to produce reliable and repeatable measurements, despite removing the manual perception of laxity. The FAD also provided additional information about the actual moment applied. This information may have a role in improving the balancing techniques of TKA and the management of collateral ligament injuries with regard initial diagnosis and grading as well as rehabilitation. Finally, the results suggest that following use of the FAD, more experienced clinicians returned to applying their usual manual force, while trainees appeared to use this augmented feedback to adapt their technique. Therefore this technique could be a way to harness the experience of senior clinicians and use it to enhance the perceptive skills of more junior trainees who do not have the benefit of this knowledge

Assessment of coronal knee laxity via manual stress testing is commonly performed during joint examination. While it is generally accepted that the knee should be flexed slightly to assess its collateral restraints, the importance of the exact degree of flexion at time of testing has not been documented. The aim of this study therefore was to assess the effect of differing degrees of knee flexion on the magnitude of coronal deflection observed during collateral stress testing. Using non-invasive infrared technology, the real-time coronal and sagittal mechanical femorotibial (MFT) angles of three asymptomatic volunteers were measured. A single examiner, blinded to the real-time display of coronal but not sagittal alignment, held the knee in maximum extension and performed manual varus and valgus stress manoeuvres to a perceived end-point. This sequence was repeated at 5° increments up to 30° of flexion. This provided unstressed, varus and valgus coronal alignment measurements as well as overall envelope of laxity (valgus angle – varus angle) which were subsequently regressed against knee flexion. Regression analysis indicated that all regression coefficients were significantly different to zero (p < 0.001). With increasing knee flexion, valgus MFT angles became more valgus and varus MFT angles became more. The overall laxity of the knee in the coronal plane increased approximately fourfold with 30° of knee flexion. The results demonstrated that small changes in knee flexion could result in significant changes in coronal knee laxity, an observation which has important clinical relevance and applications. For example the assessment of medial collateral ligament (MCL) injuries can be based on the perceived amount of joint opening with no reference made to knee flexion at time of assessment. Therefore, close attention should be paid to the flexion angle of the knee during stress testing in order to achieve a reliable and reproducible assessment

Purpose. Operative treatment of Lisfranc joint injuries typically includes reduction and stabilization of the medial and middle columns of the midfoot. Mobility of the lateral column is preserved where possible, such that indications for lateral column stabilization rely upon the surgeons assessment of instability. In this case series, the indication for lateral column stabilization was defined by the results of an intra-operative stress test. The purpose of this study was to determine whether an intra-operative fluoroscopic stress test of the lateral column was sufficient to determine the need for internal fixation of the lateral column in Lisfranc joint injuries. Method. 35 adult patients with Lisfranc injuries operated in our centre by a single surgeon from 2005–2009 were reviewed. All patients had unstable midfoot fracture dislocations, treated by reduction and internal fixation including an intra-operative stress examination to determine the need for lateral column fixation. Patients were contacted for clinical and radiographic review at a mean of 31 months post injury. Functional outcome was assessed using general and joint-specific outcome tools (AOFAS midfoot score and LEM). Radiographic review included analysis of joint displacement and arthritic changes in preoperative, postoperative, and most recent radiographs. Results. Pre-operative imaging demonstrated displacement of the lateral column in 25 / 35 patients. Nineteen of these 25 had a stable reduction of the lateral column following medial and middle column fixation, based upon an intra-operative stress examination. Only 6 patients had persistent instability; these were treated with lateral column stabilization. Reduction of the lateral column was maintained at final follow up in 100 percent of 35 patients. Lateral midfoot pain was present in 5/6 patients requiring lateral fixation, compared to 1/(19) patient who did not require lateral fixation. AOFAS midfoot scores (mean) were 80 15. in patients with no evidence of lateral column instability, 79 15. in patients with preoperative displacement but a negative stress examination, and 77 18 in patients requiring lateral fixation (p>0.05). Post-traumatic arthrosis was present in 3/10 patients with no evidence of lateral column instability, 4/19 patients with preoperative displacement but a negative stress examination, and 4/6 in patients requiring lateral fixation (p>0.05). Conclusion. The decision to stabilize the lateral column during surgery on Lisfranc injuries was aided by an intra-operative fluoroscopic stress examination. Based upon the stress examination, 19 / 25 patients who had a displaced lateral column at the time of presentation avoided lateral fixation. None of these 19 patients treated without lateral fixation lost reduction in the follow up period. A fluoroscopic intra operative stress test safely reduced the need for lateral column fixation in displaced Lisfranc joint injuries

Prior to TJR, clinical cardiovascular risk assessment is typically limited by severe exercise restrictions. Noninvasive pharmacological cardiovascular stress tests may predict major perioperative cardiovascular events in patients undergoing orthopaedic surgery. We undertook a pilot study to inform the feasibility of a large prospective cohort study. Patients were eligible if they were aged > forty-five, undergoing elective TJR, and had known atherosclerotic disease or risk factors for atherosclerotic disease. We recruited patients at the Hamilton Health Sciences, Henderson Hospital. Prior to surgery patients underwent dipyridamole stress perfusion imaging and dobutamine stress echocardiography. For both tests the interpreters evaluated seventeen myocardial segments and were blinded to information about patients’ clinical risk factors. The attending surgeons and research personnel following patients after surgery were blinded to results of the noninvasive pharmacological cardiovascular stress tests. All patients had an ECG performed and troponin T drawn six to twelve hours postoperatively and on the first, second and third days after surgery. Starting in November 2005 we recruited thirty patients over six months; seventeen (57%) patients were male, twenty-one (70%) underwent TKA, and nine (30%) underwent THA. The length of surgery was seventy-two (SD 38) minutes and the length of hospital stay was five (SD 3) days. We successfully followed all patients to thirty days after surgery. Three patients (10%; 95% CI, 3–26%) suffered a perioperative myocardial infarction. Twenty nine patients underwent dipyridamole stress perfusion imaging prior to surgery; a reversible defect involving 30–50% of the myocardium increased the likelihood of a perioperative myocardial infarction (likelihood ratio [LR] 4.0; 95% CI, 1.2–13.3). Twenty-six patients underwent dobutamine stress echo-cardiography; a reversible defect increased the likelihood of a perioperative myocardial infarction (LR 4.0; 95% CI, 0.7–22.9). This pilot study demonstrates the need for, and feasibility of, a large prospective cohort study to determine if preoperative noninvasive pharmacological cardiovascular stress testing has additional predictive value, beyond clinical variables, for the occurrence of myocardial infarction in patients undergoing major hip and knee surgery

Postero-lateral rotator instability (PLRI) is the most common pattern of recurrent elbow instability. Unfortunately, current imaging to aid PLRI diagnosis is limited. We have developed an ultrasound (US) technique to measure ulnohumeral joint gap with and without stress of the lateral ulnocollateral ligament. We sought to define lateral ulnohumeral joint gap measurements in the resting and stressed state to provide insight into how US may aid diagnosis of PLRI. Sixteen elbows were evaluated in eight healthy volunteers. Lateral ulnohumeral gap was measured on US in the resting position and with posterolateral drawer stress test maneuver applied. Joint laxity was calculated as the difference between stress and rest conditions. Measurements were performed by two independent readers with comparison performed between stress and rest positions. A highly significant difference in ulnohumeral gap was seen between stress and rest conditions (Reader 1: p < 0 .0001 and Reader 2: p=0.0002) with median values of 2.93 mm and 2.50 mm at rest and 3.92 mm and 3.40 mm at stress for Reader 1 and 2 respectively. Median joint laxity was 1.02 mm and 0.74 mm respectively for each reader. Correlation and agreement between readers was good. This study provides key new insight into use of US for diagnosis as PLRI as it defines normal ulnohumeral distances and demonstrates widening when applying the posterolateral drawer stress maneuver. Further evaluation of this technique is required in patients with PLRI

Confirmation of cervical stability in multiple trauma patients is often difficult. Prolonged collar immobilization of these patients is often required. Missed injuries can be catastrophic. Since January 2000, the senior author has regularly applied a modification of the classical White & Panjabi stretch test in the operating room as a method of assessing cervical stability in qualifying trauma patients. Review of the first thirty cases finds two cases of stable ligamentous injury identified which would have otherwise been missed, a mean of almost two weeks’ collar immobilization eliminated and no missed instabilities, with no complications or assessment failures to date. The purpose of this study was to present the protocol and preliminary results of a modified White & Panjabi cervical stretch test in the assessment of cervical instability in multiple trauma patients. Multiple trauma patients having no radiographic evidence of cervical instability on static imaging are routinely protected in hard collars until able to cooperate with clinical assessment and/or undergo flexion/extension radiographs for concern to possible discoligame-nous instability in the neck. Beginning in January 2000, such patients who were going to the operating room were routinely assessed with a stress test incorporating fluoroscopically-controlled axial distraction to tensile limit of the neck followed by maximum passive flexion and extension stressing. In the absence of intersegmental hypermobility, cervical precautions and immobilization were considered unnecessary and discarded. Chart documentation was reviewed for outcome and complications after discharge from the hospital. To date thirty-two tests have been performed and twenty-six cases had complete chart documentation available for review. No complications of the procedure and no missed instabilities have been identified. An average of thirteen days’ collar immobilization were eliminated by this protocol. Two cases of ligamentous hypermobility without instability were identified, one at O/C1 and the other at C5/6; both patients were treated observationally and have done well. One case of an undisplaced C2 pedicle fracture in a massively traumatized geriatric case was confirmed as stable on the day of injury, eliminating the need for collar support until the patient died of multiple organ failure twenty-one days later. Two patients went on to have neck pain complaints on regaining consciousness, but could be reassured that there was no instability. The operating-room cervical stress test is a practical and safe maneuver that can eliminate the requirement for collar immobilization in obtunded trauma patients, safely identify subtle ligamentous injuries without frank instability, and confirm stability in cases of undisplaced fracture. The operating-room cervical stress test is an effective tool in screening trauma patients for such injuries. It does not require access to MRI technology and can be used in any hospital with an operating room. Prolonged cervical collar immobilization and missed discoligamentous injuries of the neck in multiple trauma patients can be eliminated with the application of this test

The requirement for release of collateral ligaments to achieve a stable, balanced total knee replacement has been reported to arise in about 50% to 100% of procedures. This wide range reflects a lack of standardised quantitative indicators to determine the necessity for a release. Using recent advances in computerised navigation, we describe two navigational predictors which provide quantitative measures that can be used to identify the need for release. The first was the ability to restore the mechanical axis before any bone resection was performed and the second was the discrepancy in the measured medial and lateral joint spaces after the tibial osteotomy, but before any femoral resection. These predictors showed a significant association with the need for collateral ligament release (p < 0.001). The first predictor using the knee stress test in extension showed a sensitivity of 100% and a specificity of 98% and the second, the difference between medial and lateral gaps in millimetres, a sensitivity of 83% and a specificity of 95%. The use of the two navigational predictors meant that only ten of the 93 patients required collateral ligament release to achieve a stable, neutral knee

Background and purposes. Central Sensitization (CS) may occur in patients with Chronic Low Back Pain (CLBP). Functional capacity these patients is limited. However, the association of CLBP with functioning assessed via lifting and aerobic capacity tests has been moderately explained and results are contradictory. Let alone pain response following strenuous exercise. Finally, whether CS is associated with either or both lifting and aerobic capacities is unknown. To analyze the relationship between CS, and lifting and aerobic capacities in patients with CLBP. To describe pain response to strenuous exercise in patients with CLBP. Methods. Cross-sectional observational study. CS, lifting and aerobic capacities, and pain response were respectively measured with Central Sensitization Inventory (CSI), floor-to-waist lifting test, Cardiopulmonary Exercise Test (CPET), and Pain response questionnaire. Statistical analyses:. Stepwise-forward multiple regression with lifting and aerobic capacities (dependent), CSI (independent), physical, work- and disability-related characteristics (covariates);. Paired t-test of pain response before CPET pain to immediately and 24h after, and correlation of the changes with CSI. Results and Conclusion. 43 patients were measured. Higher CSI was associated with lower lifting (r=−0.16) and aerobic capacity (r=−0.06) performance after controlling for confounders. Explained variance were 64% and 42% respectively. Immediate pain response slightly decreased in the low back in response to strenuous exercise whereas it significantly increased in the upper legs; diffuse noxious inhibitory control could possibly explain such change. 24-hr pain response revealed no significant differences. CSI was found to be negatively associated with low back immediate pain response (r=−0.13) change. No conflicts of interest. No funding obtained

Purpose of the study: The purpose of this prospective study was to evaluated the risk of fracture of 22.2 mm Delta ceramic heads. Material and methods: A preclinical study was performed on twenty 22.2 mm Delta ceramic femoral heads with a medium neck with 20 22.2 mm Delta ceramic femoral heads with a short neck. A V40TM cone was used in all cases with a 5 40 angle. In vitro tests consisted in the assessment of the fracture force under static pressure before and after stress tests, and with a static force shock test (Charpy model) simulating a microseparation during subluxation phenomena. Between April 2007 and April 200, a consecutive series of 55 composite Delta heads were used in 55 patients undergoing cemented total hip arthroplasty (THA). A polyethylene cup was sterilised under vacuum at 3 Mrads with a post-radiation temper (Duration. ®. ), and a stainless steel femoral piece with a highly polished surface and a V40TM Morse cone (Legend. ®. ). This series issued from a randomised prospective study designed to compare wear with 22.2mm Delta ceramic heads with stainless steel heads with the same diameter. Inclusion criteria were age < 75 years, degenerative disease on naive hip and patient residing in France. Mean patient age was 59.2±6.9 years (range 44–70). Results: The resistance of the 22.2 mm heads was significantly less during the static tests before and after the stress tests. Nevertheless, the mean resistance was higher than the FDA recommendations of 46K. The tests simulating a microseparation showed a significantly superior resistance for the 22.2 mm heads. All patients had from 1 to 2 years follow-up (usual delay for 80% of in vivo ceramic fractures). There were no cases of femoral head fracture in this series. There were no cases of early wear at this same follow-up and no case of femoral or acetabular osteolysis. Discussion and Conclusion: The results of this study indicate that the resistance of the 22.2mm ceramic Delta heads is very much superior to the recommendations for in vitro tests. In this series, the risk of fracture in vivo remained nil to two years follow-up. The pertinence of this ceramic implant for decreasing polyethylene wear in vivo is under evaluation

Introduction Traumatic dislocation of knee is a complex injury challenging the skills of even the experienced surgeons. Our category of Traumatic dislocation of knee is combined ACL, PCL MCL ± other ligament injuries. Aims and objectives 1. To accurately diagnose Multiliga-mentous Knee injuries. 2. To achieve optimal functional results in complex knee ligament injuries. Materials and Methods: We have treated 37 cases of multiligamentous knee injuries, The mechanism is low energy road traffic accident. Age range from 20 to 64 yrs. Diagnosis by history and clinical tests (Drawers, valgus/Varus stress tests, rotary tests, recurvatum and Lachmann’s). Investigations:- X-rays and MRI and Diganostic Arthroscopy. MRI. Is not routine. Isolated injuries are excluded from the study. Surgery performed with in less than 1week of injury. In Chronic cases between 2–3 months Meticulous pre-op and skin Incision plan is necessary. Incisions were long oblique incision in the medial aspect for repair of the Postero medial complex, Medial collateral ligament and medial patellar retinaculae. Single incision techniques for primary ACL reconstruction with bone Patellar tendon bone graft,. Post –OP: Programmed physio protocol upto 3months. Complications: Pain at the staple site was the most common problem. None warranted removal. No cases of subjective instability/pain was reported. Post Op Assessment Average range of motion 120 degree achieved of 3 months. gentle nterior drawer’s / Lachmann’s / varus /valgus / stress test for laxity at 3 months and for instability at 6months.One leg hop test at 6 months. Posterior drawers / were positive for all patients with PCL injury due to the delayed reconstruction. Average follow-up of 15months. Lysholm knee score average of 84points,Keating’s knee score is average 82 on multiligamentous reconstructions of knee joint. Conclusion: Excellent results achieved with staged Repair/Reconstruction with PCL at 2nd stage, all other ligaments as 1st stage

Instability currently represents the most frequent cause for revision total knee replacement. Instability can be primary from the standpoint of inadequately performed collateral and/or posterior cruciate ligament balancing during primary total knee replacement or it may be secondary to malalignment/loosening which can develop later progressive instability. Revision surgery must take into consideration any component malalignment that may have primarily contributed to instability. Care should be given to assessing collateral ligament integrity. This can be done during physical examination by radiological stress testing to see if the mediolateral stress of the knee comes to a good endpoint. If there is no sense of a palpable endpoint, then the surgeon must assume structural incompetency of the medial or lateral collateral ligament or both. In posterior cruciate retaining knees, anteroposterior instability must be assessed. For instability, most revisions will require a posterior cruciate substituting design or a constrained condylar design that is unlinked. However, if the patient displays considerable global instability, a linked, rotating platform constrained total knee replacement design will be required. Recent data has shown that the rotating hinges work quite well in restoring stability to the knee with maintenance of the clinical results over a considerable length of time. Intramedullary stems should be utilised in most cases when bone integrity is suspect and insufficient. Infection should be ruled out by aspiration and off of antibiotics prior to any revision operation, especially if loosening of the components represents the cause of instability. The surgeon should attempt to restore collateral ligament balance whenever possible as this yields the best clinical result

Anatomical referencing, component positioning, limb alignments and correction of mechanical axes are essential first steps in successful computer assisted navigation. However, apart from basic gap balancing and quantification of ranges of motion, routine navigation technique usually fails to use the full potential of the registered information. Enhanced dynamic assessment using an upgraded navigation system (Brainlab V. 2.2) is now capable of producing enhanced ‘range of motion’ analysis, ‘tracking curves’ and ‘contact point observations’. ‘Range of motion analysis’ was performed simultaneously for both tibio-femoral and patella-femoral joints. Other dynamic information including epicondylar axis motion, valgus and varus alignments, antero-posterior tibio-femoral shifts, as well as flexion and extension gaps were simultaneously stored as a series of ‘tracking curves’ throughout a full range of motion. Simultaneous tracking values for both tibiofemoral and patellofemoral motion was also obtained after performing registration of the prosthetic trochlea. However, there seems to be little point in carrying out such observations without fully assessing joint stability by applying controlled force to the prosthetic joint. Therefore, in order to fully assess ‘potential envelopes of motion’, observations have been made using a set of standardised simple dynamic tests during insertion and after final positioning of trial components. Also, such tests have been carried out before and after any necessary ligament balancing. Firstly, the lower leg was placed in neutral alignment and the knee put through a flexion-extension cycle. Secondly the test was repeated but with the lower leg being placed into varus and internal rotation. The third test was performed with the lower leg in valgus and external rotation. Force applied was up to the point where resistance occurred without any gross elastic deformation of capsule or ligament in a manner typical of any surgeon assessing the stability of the construct. Also a passive technique of using gravity to ‘Drop-Test’ the limb into flexion and extension gave useful information regarding potential problems such as blocks to extension, over-stuffing of the extensor mechanism and tightness of the flexion gap. All the definitive tests were performed after temporary medial capsular closure. Ten total knee arthroplasties have been studied using this technique with particular reference to the patterns of instability found before, during and after adjustments to component positioning and ligament balancing. Marked intra-operative variation in the stability characteristics of the trial implanted joints has been quantified before correction. These corrections have been analysed in terms of change in translations, rotations and contact points induced by any such adjustments to components and ligament. Certain major typical patterns of instability have begun to be identified including excessive rotational and translational movements. Instability to valgus and external rotational stress was found in two cases and to varus and internal rotational stress in one case before correction. In particular, surprising amounts of edge loading in mid-flexion under stress testing has been identified and corrective measures carried out. Reductions in paradoxical tibio-femoral antero-posterior motion were also observed. Global instability and conversely tightness were also observed in early stages of surgery. Adjustments to component sizes, rotations, tibial slope angles and insert thickness were found to be necessary to optimise range of motion and stability characterisitics on an almost case-by-case basis. Two cases were identified where use of more congruent or stabilised components was necessary. Observation of quite marked loss of contact between tibia and femur was seen on the lateral side of the knee in deep flexion in several cases. Patellar tracking was also being observed during such dynamic tests and in two cases staged partial lateral retinacular releases were carried out to centre patellar tracking on the prosthetic trochlea. Although numbers in this case series are small, it has been possible to begin to observe, classify and quantify patterns of instability intra-operatively using simple stress tests. Such enhanced intra-operative information may in future make it possible to create algorithms for logical and precise adjustments to ligaments and components in order to optimise range of motion, contact areas and stability in TKR

Background. The Bundled Payments for Care Improvement (BPCI) was developed by the US Center for Medicare and Medicaid (CMS) to evaluate a payment and service delivery model to reduce cost but preserve quality. 90 day postoperative expenditures are reconciled against a target price, allowing for a monetary bonus to the provider if savings were achieved. The surgeon is placed in a position to optimize the patients preoperatively to minimize expensive postoperative cardiovascular readmissions in a high risk population. Traditionally, surgeons request that primary care providers medically clear the patient for surgery with or without additional cardiology consultation, without dictating specific testing. Typical screening includes an EKG, occasionally an echocardiogram and nuclear stress test, and rarely a cardiac catheterization. Our participation in the BPCI program for total hip and knee replacement surgeries since 1/1/15 has demonstrated a significant number of patients having readmissions for cardiac events. Objective. To determine the medical effectiveness and cost savings of instituting a new innovative cardiac screening program (Preventive Cardio-Orthopaedics) for total hip and knee replacement patients in the BPCI program and to compare result to those managed in the more traditional fashion. Methods. The new screening program was instituted on 11/1/17 directed by an advanced cardiac imaging cardiologist (EH). Testing included an electrocardiogram, echocardiogram, carotid and abdominal ultrasound, and coronary computed tomography angiography (CCTA). If needed, a 3 day cardiac rhythm monitor was also performed. Four of the ten physicians in our group performing hip and knee replacement surgeries participated. Charts of readmitted patients were reviewed to determine past medical history, method of cardiac clearance, length and cost of readmission. Results. 1,361 patients had total hip or knee replacement in the BPCI program between 1/1/15 and 1/28/18 and all had complete 90 day postoperative readmission data supplied by the CMS, with 25 of these patients evaluated through the Preventive Cardio- Orthopaedics program. 12 (0.90%) screened via the traditional cardiac program had a cardiac event readmission. The average readmission hospital stay was 3.67 days at a total cost of $69,378. 7 of 12 had a preoperative clearance by a cardiologist. In 9 of the 12 patients, the only preoperative cardiac screening tool performed was an electrocardiogram. None of these 25 patients evaluated through the new program has been readmitted. 84 more patients have been evaluated in this program since 1/28/18, but 90 day readmission data is still incomplete. Preliminary data suggests that the highest risk in these patients is not severe coronary artery disease, but atrial fibrillation, hypertension with left ventricular hypertrophy, and cardiac plaques with ulceration. Conclusions. Risk sharing programs have forced joint replacement surgeons to take a more active role in optimizing their patients medically; otherwise they will be penalized with a decreased reimbursement. Traditionally, we have abdicated this responsibility to primary care and cardiology physicians but have noted a high readmission risk with a cardiac event. In response, we have begun using a unique cardiac screening model. Our preliminary experience predicts fewer cardiac readmissions thereby improving care, and at a lower cost