Background:. The origin of a valgus deformity affects the algorithmic and individualized approach used in total knee arthroplasty in valgus knees. We developed a new physical examination technique, the swing test, to evaluate whether valgus malalignment is present when the knee flexes. Methods:. We performed the swing test on 44 valgus knees in 44 consecutive patients, and we conducted traditional malalignment analysis on each patient's long-film radiographs and computed tomography images to evaluate origin of valgus deformity. We did a diagnostic test to compare the results of the swing test with those of traditional malalignment analysis. Results:. For the swing test, there were positive findings in 22 cases and negative findings in the other 22 cases, whereas for traditional malalignment analysis, there were positive findings in 26 cases and negative findings in 18. The sensitivity, specificity, and accuracy for the swing test were 84.6%, 100%, and 90.9%, respectively. Conclusions:. The swing test is an effective technique in evaluating whether valgus deformity exists when the knee is flexed. Level of Evidence: Level III. See Instructions to Authors for a complete description of levels of evidence

Multiligament knee injuries (MLKI) are rare and life-altering injuries that remain difficult to treat clinically due to a paucity of evidence guiding surgical management and timing. The purpose of this study was to compare injury specific functional outcomes following early versus delayed surgical reconstruction in MLKI patients to help inform timing decisions in clinical practice. A retrospective analysis of prospectively collected data from patients with MLKIs at a single academic level 1-trauma center was conducted. Patients were eligible for inclusion if they had an MLKI, underwent reconstructive surgery either prior to 6wks from injury or between 12weeks and 2 years from injury, and had at least 12months of post-surgical follow-up. Patients with a vascular injury, open injuries or associated fractures were excluded. Study participants were stratified into early (12 weeks - 2 years from injury). The primary outcome was patient reported, injury specific, quality of life in the form of the Multiligament Quality of Life questionnaire (MLQOL) and its four domains (Physical Impairment, Emotional Impairment, Activity Limitations and Societal Involvement). We secondarily analyzed differences in the need for manipulation under anesthesia, and reoperation rates, as well as radiographic Kellgren Lawrence (KL) arthritis grades, knee laxity grading and range of motion at the most recent follow-up. A total of 131 patients met our inclusion criteria, all having had surgery between 2006 and 2019. There were 75 patients in the early group and 56 in the delayed group. The mean time to surgery was 17.6 ± 8.0 days in the early group versus 279 ± 146.5 days in the delayed. Mean postoperative follow-up was 58 months. There were no significant differences between early and delayed groups with respect to age (34 vs. 32.8 years), sex (77% vs 63% male), BMI (28.3 vs 29.7 kg/m2), or injury mechanism (p>0.05). The early surgery group was found to include more patients with lateral sided injuries (n=49 [65%] vs. n=23 [41%]; p=0.012), a higher severity of Schenck Classification (p=0.024) as well as nerve injuries at initial presentation (n=35 [49%] vs n=8 [18%]; p0.05), when controlling for age, sex, Schenck classification, medial versus lateral injury, and nerve injury status. In terms of our secondary outcomes, we found that the early group underwent significantly more manipulations under anesthesia compare with the delayed group (n=24, [32%] vs n=8 [14%], p=0.024). We did not identify a significant difference in physical examination laxity grades, range of motion, KL grade or reoperation rates between groups (p>0.05). We found no difference in patient reported outcomes between those who underwent early versus delayed surgery following MLKI reconstruction. In our secondary outcomes, we found significantly more patients in the early surgery group required a manipulation under anesthesia following surgery, which may indicate a propensity for arthrofibrosis after early MLKI reconstruction

Multiligament knee injuries (MLKI) are rare and life-altering injuries that remain difficult to treat clinically due to a paucity of evidence guiding surgical management and timing. The purpose of this study was to compare injury specific functional outcomes following early versus delayed surgical reconstruction in MLKI patients to help inform timing decisions in clinical practice. A retrospective analysis of prospectively collected data from patients with MLKIs at a single academic level 1-trauma center was conducted. Patients were eligible for inclusion if they had an MLKI, underwent reconstructive surgery either prior to 6wks from injury or between 12weeks and 2 years from injury, and had at least 12months of post-surgical follow-up. Patients with a vascular injury, open injuries or associated fractures were excluded. Study participants were stratified into early (<6wks from injury) and delayed surgical intervention (>12 weeks – 2 years from injury). The primary outcome was patient reported, injury specific, quality of life in the form of the Multiligament Quality of Life questionnaire (MLQOL) and its four domains (Physical Impairment, Emotional Impairment, Activity Limitations and Societal Involvement). We secondarily analyzed differences in the need for manipulation under anesthesia, and reoperation rates, as well as radiographic Kellgren Lawrence (KL) arthritis grades, knee laxity grading and range of motion at the most recent follow-up. A total of 131 patients met our inclusion criteria, all having had surgery between 2006 and 2019. There were 75 patients in the early group and 56 in the delayed group. The mean time to surgery was 17.6 ± 8.0 days in the early group versus 279 ± 146.5 days in the delayed. Mean postoperative follow-up was 58 months. There were no significant differences between early and delayed groups with respect to age (34 vs. 32.8 years), sex (77% vs 63% male), BMI (28.3 vs 29.7 kg/m. 2. ), or injury mechanism (p>0.05). The early surgery group was found to include more patients with lateral sided injuries (n=49 [65%] vs. n=23 [41%]; p=0.012), a higher severity of Schenck Classification (p=0.024) as well as nerve injuries at initial presentation (n=35 [49%] vs n=8 [18%]; p<0.001). Multivariable linear regression analyses of the four domains of the MLQOL did not demonstrate an independent association with early versus delayed surgery status (p>0.05), when controlling for age, sex, Schenck classification, medial versus lateral injury, and nerve injury status. In terms of our secondary outcomes, we found that the early group underwent significantly more manipulations under anesthesia compare with the delayed group (n=24, [32%] vs n=8 [14%], p=0.024). We did not identify a significant difference in physical examination laxity grades, range of motion, KL grade or reoperation rates between groups (p>0.05). We found no difference in patient reported outcomes between those who underwent early versus delayed surgery following MLKI reconstruction. In our secondary outcomes, we found significantly more patients in the early surgery group required a manipulation under anesthesia following surgery, which may indicate a propensity for arthrofibrosis after early MLKI reconstruction

Latissimus dorsi anterior to major transfers have been advocated in the setting of loss of external rotation and elevation in conjunction with reverse shoulder replacement. Reverse shoulder replacement is a prosthesis specifically designed for shoulders with poor rotator cuff function. In the vast majority of cases, some teres minor function at the minimum is maintained in shoulders destined for a reverse shoulder replacement. However, in certain circumstances there is complete loss of any external rotation, and a muscle transfer can be performed in order to restore some external rotation function. A reverse shoulder replacement in the absence of any rotator cuff function goes into obligate internal rotation with elevation. A minimum of external rotation strength is necessary in order to maintain the arm in normal rotation. The first tip is patient selection. Physical examination of active external rotation, external rotation strength and forward elevation should be just performed. A latissimus transfer is indicated in patients who cannot maintain their arm in neutral to at least a few degrees of external rotation. A lag sign is another physical examination finding which can indicate complete loss of rotator cuff function. The latissimus dorsi transfer is performed by first identifying and releasing the latissimus from its insertion on the anterior humerus. The arthroplasty is performed. The passage for the latissimus muscle is developed carefully and being mindful of the axillary nerve in particular. The latissimus is directed inferior to the nerve and around the medial and posterior aspect of the proximal humerus. Different ways of securing the transfer to the humerus have been described including bone tunnels and anchors. Often it is easier to place the anchors and/or the bone tunnels prior to inserting the humeral prosthesis. The latissimus is secured in the new position, enabling it to participate in external rotation. The value of this is difficult to clearly establish. Most studies are evidence level IV and there are no good comparative studies in a controlled patient population. This is a good option for shoulders with no active external rotation, but they may increase overall complication rate. Complications include dislocation, infection, and transient nerve palsy

Introduction. Torsional malalignment syndrome (TMS) is a unique combination of rotational deformities in the lower limb, often leading to severe patellofemoral joint pain and disability. Surgical management of this condition usually consists of two osteotomies in each affected limb, with simultaneous correction of both femoral anteversion and external tibial torsion. However, we believe that a single supratubercular osteotomy followed by tibial derotation with the Taylor Spatial Frame (TSF) can be used to provide a significant improvement in both appearance and function. Materials and Methods. This is a retrospective case analysis in which we will be reviewing 16 osteotomies performed by one surgeon between 2006 and 2017. The study includes 11 patients with a mean age of 16.7 ± 0.8 years. Pre and post-operatively, patients were fully evaluated through history and physical examination, and CT rotational profiling. Statistical analyses were performed in order to determine whether or not any observed clinical or cosmetic improvements were statistically significant. Results. The results show significant improvements in scores reported on post-operative functional assessment, with mean Oxford Knee Score (OKS) increasing by 18.3 and mean Kujala Anterior Knee Pain Scale (AKPS) also increasing by 31.4. In addition to this, post-operative clinical assessment showed a reduced thigh-foot angle (TFA) in all cases, by a mean value of 31.9o. The angle of the transmalleolar axis (TMA) was successfully reduced in 14/16 cases, by a mean value of 8.6o. Statistical analysis showed all of these results to be statistically significant where p<0.05. Conclusions. The results show that supratubercular osteotomy, followed by gradual correction with TSF, can be used to provide a significant improvement in both appearance and function for patients suffering from TMS

Purpose. Although multiple surgical options exist for chronic static scapholunate dissociation, no single procedure has been found to be superior clinically or kinematically. We hypothesize that the reduction and association of the scaphoid and lunate (RASL procedure) is a safe and effective procedure that improves function and alleviates pain in the injured wrist. The purpose of this study is to report long-term follow-up of patients undergoing the RASL procedure over a 20-year period. Method. Between December 1991 and September 2008, the senior author performed 36 RASL procedures for chronic static scapholunate dissociation. This reconstruction involves reduction of the rotational deformity and diastasis between the scaphoid and lunate through a dorsal approach to the wrist. Maintenance of reduction is accomplished with a cannulated, headless, smooth-shafted compression screw directed from the scaphoid to the lunate along the anatomic axis of rotation between the two bones. For the purposes of this study, patients were evaluated by visual analog pain scale (VAS), Disability of the Arm, Shoulder and Hand questionnaire (DASH), SF-36 health survey, physical examination and radiographs. Results. Thirty-two of 36 patients were available for questionnaires and 23 available for questionnaires and physical examination, with an average time to final follow-up of 6.2 years post-operatively. The mean DASH score was 16.6, and other patient-based outcomes showed similarly favorable results. Range of motion was well preserved with 80% of the contralateral flexion-extension arc being maintained in those available for physical examination. Grip strength was well preserved at 90% of the contralateral side. X-rays showed significant decreases in scapholunate gap (p < 0.001) and scapholunate angle (p < 0.001) as compared to preoperative films. In the 32 patients followed, there were 2 treatment failures going on to have salvage procedures for progression to scapholunate advanced collapse deformities. These patients were included in the final analysis. Conclusion. The RASL procedure is a safe and effective treatment for chronic static scapholunate dissociation. It re-aligns the scaphoid and lunate, restores function, reduces pain, and appears to be robust over time

Lymph node metastasis are a rare occurrence in soft tissue sarcomas of the extremity, arising in less than 5% of patients. Few studies have evaluated the prognosis and survival of patients with a lymph node metastasis. Early reports compared lymph node involvement to lung metastasis, while others suggested a slightly better outcome. The purpose of this study was to evaluate the impact of lymph node metastasis on patient survival and to investigate the histologic and clinical features associated with lymph node involvement. A retrospective review was done of the prospectively collected soft tissue sarcoma database at our institution. Two thousand forty-five patients had surgery for soft tissue sarcoma of an extremity between January 1986 and August 2017. Included patients either presented with a synchronous lymph node metastasis or were diagnosed with a lymph node metastasis after their initial treatment. Demographic, treatment, and outcome data for patients with lymph node involvement were obtained from the clinical and radiographic records. Lymph node metastases were identified as palpable adenopathy by physical examination and were further characterized on cross-sectional imaging by computed tomography (CT) or magnetic resonance imaging (MRI) scans. All cases were confirmed by pathologic examination of biopsy specimens. A pathologist with expertise in sarcoma determined the histologic type and graded tumors as 1, 2, or 3. One hundred eighteen patients with a mean age of 55.7 (SD=18.9) were included in our study. Seventy-two (61.3%) out of 119 patients were male. Thirty six patients (57.1%) had lymph node involvement at diagnosis. The mean follow-up from the date of the first surgery was 56.3 months. The most common histological diagnoses were Malignant fibrous histiocytoma (35) and liposarcoma (12). Ninety eight patients (89%) underwent surgical treatment of the lymph node metastasis while 21 (17.6%) were treated with chemotherapy and/or radiation therapy. The mean survival was 52.6 months (range 1–307). Our results suggest that patients with a lymph node metastasis have a better prognosis than previously described. Their overall survival is superior to patients diagnosed with lung metastasis. A signifant proportion of patients may expect long term survival after surgical excision of lymph node metastasis. Furthermore, our study also indicates that different histological subtypes such as liposarcoma or malignant peripheral nerve sheath tumor (MPNST) may also be responsible for lymph node metastasis. Additional studies to further improve the treatment of soft tissue sarcoma nodal metastasis are warranted

Integrated Regional Orthopaedic (MSK) Assessment clinics (ROAC) are now mandated in many provinces for the assessment and triage of patients referred for total joint arthroplasty (TJA). Their introduction underscores the lack of means for Primary Care Physicians (PCP) to appropriately refer patients for surgical consideration. Thus, problems arise when patients who are clear candidates for surgery are subject to a significant extra step in the care pathway by attending a ROAC while those who have insufficient problems are also seen, contributing to costs and crowding the access portal. We postulated that a patient reported outcome measure, decision aid combined with a validated grading of a weight bearing knee X-ray would provide an inexpensive yet effective tool to significantly improve the referral process for Knee OA (compared with the current mechanism). To date we have enrolled two hundred and forty-five consenting patients to the study, all referred by their PCP to the ROAC with a diagnosis of symptomatic Knee Osteoarthritis. All patients were evaluated as per the current ROAC protocol which included a medical history, physical examination and an X-ray (standing AP, lateral and patella-femoral skyline). Prior to the visit, subjects were sent a copy of a patient decision aid, Oxford Knee Score (OKS) and requested to answer whether their current clinical status described as Patient Acceptable Symptom State (PASS2) was acceptable. All radiographs were analyzed and scored for OA severity using the validated grading from 0 – 13. Of the 245 cases, 200 completed OKS and PASS2 uestionnaires and had standing X-rays for evaluation (only 120 completed the decision aid and these were left out of this report). Of the 200 included cases, 104 were referred from the ROAC to see a surgeon. In analysis, we found that a self-reported PASS 2 answer NO and an AP X-ray graded at 6 or above predicted over 75% of those patients that were referred. This represents a 3.4 greater likelihood of referral using this simple analysis. The OKS did not modify this prediction. Thus, use of a validated grading of a standing AP X-ray along with a response, ‘readiness for surgery’ indicated 75% of patients appropriate for surgical consideration. Patients with less severe gradings are likely being unnecessarily referred to ROAC leading to overuse of scarce resources, crowding the access and adding to costs, others, who score higher, are being needlessly delayed. The ability to discreetly screen for the best possible candidates should be a continued focus of ROAC and will lead to improved use of expensive resources, overall patient care and satisfaction and the provision of tools to the PCP for appropriate referral

Physical examination is critical to formation of a differential diagnosis in patients with ulnar-sided wrist pain. Although the specificity and sensitivity of some of those tests have been reported in the literature, the prevalence of positive findings of those provocative maneuvers has not been reported. The aim of the study is to find the prevalence of positive findings of the most commonly performed tests for ulnar sided wrist pain in a population presenting to UE surgeon clinics, and to correlate those findings with wrist arthroscopy findings. Patients with ulnar sided wrist pain were identified from a prospective database of patients presented with wrist pain from September 2014. Prevalence of positive findings for the following tests were gathered: ECU synergy test, ECU instability test (Ice cream and Fly Swatter), Lunotriquetral ballottement, Kleinman shear, triquetrum tenderness, triquetrum compression test, triquetral-hamate tenderness, pisotriquetral shuck test, ulnar fovea test, ulnocarpal impaction (UCI) maneuver, UCI maneuver with fovea pressure (ulnar carpal plus test), piano key sign. A subgroup was then created for those who underwent wrist arthroscopy, and analysis of the sensitivities, the specificities and the predictive values of these provocative tests was carried out with correlation to arthroscopic finding. Prevalence of ECU instability tests was t 1.13% (ice cream scoop) and 1.5% (fly swatter). Lunotriquetral ballottement test's positive findings range from 4.91% (excessive laxity) to 14.34% (pain reproducing symptoms. The Kleinman shear test yielded pain in 13.58% of patients, and instability in only 2.26%. Triquetrum compression test reproduces pain in 32.83% of patients, and triquetral-hamate tenderness reproduced pain in 13.21%. Pisotriquetral grind test yields 15.85% positive findings for pain, and 10.57% for crepitus with radioulnar translation. The ulnar fovea test revealed pain in 69.05% of cases. The UCI maneuver yielded pain in 70.19%. The UCI maneuver plus ulnar fovea test reproduced pain in 80.38% of cases. Finally, the piano key sign yields positive finding in 2.64% of cases. For patients who underwent surgery, sensitivities, specificities and predictive values were calculated based on arthroscopic findings. The lunotriquetral ballottement test has 59.6% sensitivity, 39.6% specificity, 20.3% positive predictive value and 85.4% negative predictive value. The sensitivity of Kleinman test was 62.4%, the specificity was 41.3%, the positive predictive value was 23.5%, and the negative predictive value was 83.2%. The sensitivity of fovea test was 94.3%, the specificity was 82.5%, the positive predictive value was 89.5% and the negative predictive value was 92.3%. The UCI maneuver plus ulnar fovea test has 96.5% sensitivity, 80.7% specificity 86.4% positive predictive value, and 95.3% negative predictive value. Among the provocative tests, the prevalence of positive findings is low in the majority of those maneuvers. The exceptions are the fovea test, the UCI maneuver, and the UCI plus maneuver. With regard to the sensitivity and the specificity of those tests, the current study reproduces the numbers reported in the literature. Of those patients who underwent wrist arthroscopy, the tests are better at predicting at the absence of injury rather than at predicting its presence

Introduction. Femoral neck impingement occurs clinically in total hip replacements (THR) when the acetabular liner articulates against the neck of a femoral stem prosthesis. This may occur in vivo due to factors such as prostheses design, patient anatomical variation, and/or surgical malpositioning, and may be linked to joint instability, unexplained pain, and dislocation. The Standard Test Method for Impingement of Acetabular Prostheses, ASTM F2582 −14, may be used to evaluate acetabular component fatigue and deformation under repeated impingement conditions. It is worth noting that while femoral neck impingement is a clinical observation, relative motions and loading conditions used in ASTM F2582-14 do not replicate in vivo mechanisms. As written, ASTM F2582-14 covers failure mechanism assessment for acetabular liners of multiple designs, materials, and sizes. This study investigates differences observed in the implied and executed kinematics described in ASTM F2582-14 using a Prosim electromechanical hip simulator (Simulation Solutions, Stockport, Greater Manchester) and an AMTI hydraulic 12-station hip simulator (AMTI, Watertown, MA). Method. Neck impingement testing per ASTM F2582-14 was carried out on four groups of artificially aged acetabular liners (per ASTM F2003-15) made from GUR 1020 UHMWPE which was re-melted and cross-linked at 7.5 Mrad. Group A (n=3) and B (n=3) consisted of 28mm diameter femoral heads articulating on 28mm ID × 44mm OD acetabular liners. Group C (n=3) and D (n=3) consisted of 40mm diameter femoral heads articulating on lipped 40mm ID × 56mm OD 10° face changing acetabular liners. All acetabular liners were tested in production equivalent shell-fixtures mounted at 0° initial inclination angle. Femoral stems were potted in resin to fit respective simulator test fixtures. Testing was conducted in bovine serum diluted to 18mg/mL protein content supplemented with sodium azide and EDTA. Groups A and C were tested on a Prosim; Groups B and D were tested on an AMTI. Physical examination and coordination measurement machine (CMM) analyses were conducted on all liners pre-test and at 0.2 million cycle intervals to monitor possible failure mechanisms. Testing was conducted for 1.0 million cycles or until failure. An Abaqus/Explicit model was created to investigate relative motions and contact areas resulting from initial impingement kinematics for each test group. Results. Effects of kinematic differences in the execution of ASTM F2582-14 were observed in the four groups based on simulator type (Figure 1) and liner design. The Abaqus/Explicit FEA model revealed notable differences in relative motions and contact points (Figure 2) between specimen components i.e. acetabular liner, femoral head, and femoral stem throughout range of motion. Acetabular liner angular change within shell-fixtures, rim deformation, crack propagation, and metal-on-metal contact between acetabular shell-fixtures and femoral stems were observed as potential failure mechanisms (Figure 3) throughout testing. These mechanisms varied in severity by group due to differing contact stresses and simulator constraints. Significance. Investigating failure mechanisms caused by altered kinematics of in-vitro neck impingement testing, due to influences of simulator type and acetabular liner design, may aid understanding of failure mechanisms involved when assessing complaints/retrievals and influence future prosthetic designs. For any figures or tables, please contact the authors directly

Identifying the core competencies of musculoskeletal medicine has been the basis for the development of the Australian Musculoskeletal Education Competencies (AMSEC) project. AMSEC aims to ensure Australian health professionals are suitably equipped through improved and appropriate education to address the increasing burden of both acute and chronic musculoskeletal disease. The AMSEC project has consisted of four distinct phases. The first two phases were consultative and highlighted concerns from medical educators, specialists and students that current curricula inadequately address the increasing scientific information base in MSK medicine and management. In phase three, Multidisciplinary Working Groups were established to detail competencies in MSK areas such as physical examination, red flag emergencies, basic and clinical science, patient education and self-management, procedural skills and rehabilitation and a web portal was developed. Phase four will see the core competencies completed, endorsed by the relevant professional colleges and integrated into Australian Medical School curricula. By bringing together experts from different groups involved in musculoskeletal education, it has been possible to agree on the core competencies required of a graduating medical student and from these determine the required underlying basic knowledge, skills and attitudes. These competencies are based on actual needs determined from current disease impact studies and the experience of professionals working in the various areas of musculoskeletal related clinical practice. This multidisciplinary and multi-professional approach, which includes consumer groups, has allowed a broader and more complete perspective of requirements. Both improved horizontal and vertical integration are facilitated and more efficient implementation is possible. By linking these core competencies to specific anatomy and basic science knowledge requirements, justification of the need to address current deficits in these areas was achieved. A standardised evidenced based approach to physical examination was developed allowing a unified approach to the resourcing and teaching of this skill by orthopaedic surgeons, rheumatologists and others. The ability to outline competency requirements vertically from medical student to resident, general practitioner and specialist is greatly facilitated by combining specialist educators with those of the universities and general practitioners. For the specialists, this approach yields excellent education leverage for very little additional effort. AMSEC has undertaken significant inter and intra disciplinary consultations to identify and classify core MSK competencies at a basic, median and advanced level of specialisation across professions. This novel national integrated model to address education needs offers many benefits and could be translated into other areas of medicine

Success in knee revision begins in the office. The initial evaluations determine the implant design and pre-operative diagnosis. The physical examination identifies the presence of instability, stiffness, extensor mechanism malfunction and previous incisions all of which influence the planned procedure. Prior to surgery arrangements are made to have all manner of revision implants, removal tools, and allograft material available. Removal of implants must be done with a focus on preserving bone stock and the extensor mechanism. Initial exposure involves release of the gutters, lateral subluxation of the patella and removal of the polyethylene insert. These maneuvers combined with a quadriceps snip provide exposure for implant removal in 80–90% of cases. More extensive exposure options include quadriceps turndown, tibial tubercle osteotomy, medial epicondylar osteotomy and a femoral peel. Tools needed for implant removal include thin osteotomes, offset osteotomes, thin saws and a high-speed bur. After polyethylene removal the femur followed by the tibia are removed. In many cases the existing well-fixed patellar component can remain. The implant cement or implant bone interface is approached for cemented and cementless implants, respectively. Tools are always directed parallel to the fixation surface. Offset osteotomes are helpful gaining access to the femoral notch when femoral pegs prevent access from the sides. Central keels or peripheral pegs can complicate tibial removal. Working completely around the keel from medial and lateral disrupts the peripheral tibial interface leaving just the central posterior metaphysis. Stacked osteotomes or a slap hammer can be used to lift the baseplate from the tibia

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

The AAOS clinical practice guideline for diagnosis of periprosthetic joint infection (PJI) and the MSIS definition of PJI were both “game changers” in terms of diagnosing PJI and the reporting of outcomes for research. However, the introduction of new diagnostic modalities, including biomarkers, prompted a re-look at the diagnostic criteria for PJI. Further there was a desire to develop an evidence-based, validated algorithm for the diagnosis of PJI. This multi-institutional study led by Dr. Jay Parvizi examined revision total joint arthroplasty patients from three academic institutions. For development of the algorithm, infected and aseptic cohorts were defined. PJI cases were defined using only the major criteria from the Musculoskeletal Infection Society (MSIS) definition (n=684). Aseptic cases underwent revision for a non-infective indication and did not show evidence of PJI or undergo a reoperation for any reason within 2 years (n=820). Risk factors, clinical findings, serum and synovial markers as well as intraoperative findings were assessed. A stepwise approach using random forest analysis and multivariate regression was used to generate relative weights for each of the various variables assessed at each stage to create an algorithm for diagnosing PJI using the 3 most important tests from each step. The algorithm was formally validated on a separate cohort of 422 patients, 222 who were treated with a 2-stage exchange for PJI who subsequently failed secondary to PJI within one year and 200 patients who underwent revision surgery for an aseptic diagnosis and had no evidence of PJI within two years and did not undergo a reoperation for any reason. The first step in evaluating PJI should include a physical examination to identify a sinus tract, followed by serum testing for C-reactive protein (cut-off value 1mg/dl), D-dimer (cut-off value 860ng/mL) and/or erythrocyte sedimentation rate (cut-off value 30mm/hr) in that order of importance. If at least one of these are elevated, or if there is a high clinical suspicion, joint aspiration should be performed, sending the fluid obtained for a synovial fluid white blood-cell (cut-off value 3,000 wbc/uL) or leukocyte esterase strip testing, polymorphonuclear percentage (cut-off value 80%) and culture. Alpha defensin did not show added benefit as a routine diagnostic test. Major diagnostic criteria are the same whereby the presence of a sinus tract or (2) positive cultures showing the same organism defines PJI. Special care should be taken in cases of ALTR (failed metal-on-metal bearing), crystalline deposition disease, inflammatory arthritis flares or slow growing organisms. In the rare cases where no fluid is obtained at the time of an attempted aspiration and revision surgery is not planned, then this is the rare scenario where nuclear imaging (my preference is an indium labeled white blood cell scan) or a biopsy can be performed. The updated definition of PJI demonstrated a higher sensitivity of 97.7% when compared to the MSIS criteria (79.3%) and the ICM definition (86.9%), with a similar specificity of 99.5%. However, just over 2% of patients examined do fall into the “inconclusive” category. The proposed diagnostic algorithm demonstrated a high overall sensitivity (96.9%) and specificity (99.5%)

Most total knee prostheses are designed to have limited congruence between the femoral and tibial components to reduce constraint, based on the widely accepted principle that “constraint causes loosening”. Studies of the normal knee, however, indicate that stability under axial load occurs mostly by the geometric conformity of the surfaces. When moving in the plane of flexion-extension, the ligaments contribute little to stability because the ligaments are in the “toe-region” of their force-displacement curve. When an “out-of-plane” load is applied (i.e., load outside the plane of flexion-extension), ligaments are “recruited” for stability by being stressed into the elastic portion of the curve to resist the load. For the traditional total knee prosthesis, because of the lack of geometric congruity, the ligaments must provide all stability by being “balanced”, i.e. tensioned into the elastic portion of the force-displacement curve. Further, they must remain in that tensioned state indefinitely, with no stretching or migration of the implant. The medial pivot knee design has a fully conforming medial “ball-in-socket” articulation that provides stability to the knee through the geometric conformity. Ligaments need not be tensioned into the elastic region of the force-displacement curve but can be left in the toe-region to be recruited for out-of-plane loads. Clinical follow-up results in patients with a medial pivot prosthesis indicate that, based on Knee Society and WOMAC scores, patients report greater than 90% satisfaction with pain and function. Further, the most satisfied patients are those who, during physical examination, display medial and lateral opening that might be classified as “mid-flexion instability” for prostheses that depend on ligament tensioning for stability

Achievement of adequate exposure in revision total knee arthroplasty is critical as it reduces the surgical time, enhances the ability for both component removal and reconstruction, and avoids devastating complications such as extensor mechanism disruption. However, this can be challenging as prior multiple surgeries and limited mobility contribute to a loss of tissue elasticity, thickened capsular envelope, and peri-articular soft tissue adhesions. A thorough pre-operative assessment of a patient's past surgical history, comorbidities, pre-operative radiographs (i.e. the presence of severe patella baja), and physical examination including range of motion, prior incisions, and soft tissue pliability are useful in determining the appropriate surgical techniques necessary for a successful revision. A systematic approach to the ankylosed knee is critical. Most techniques are geared towards mobilization of the extensor mechanism to safely displace the patella for component exposure. The initial exposure should consist of a long skin incision, a subperiosteal medial release, and debridement of suprapatellar, medial, and lateral adhesions to the femoral condyles. A lateral capsular release can prove helpful in further mobilization of the extensor mechanism. When performing a medial parapatellar arthrotomy it's important to keep in mind further extensile exposure techniques that may be required. For example, the arthrotomy should not extend proximally into the vastus intermedius or rectus femoris in the event that a quadriceps snip technique is to be used as this can compromise the ability to repair this exposure. Despite a large exposure and release of adhesions, sometimes the extensor mechanism remains at risk of rupture and adequate visualization cannot be obtained. In this event, extensile exposures such as a quadriceps snip, quadriceps turndown or tibial tubercle osteotomy are considered. The location of the patella often dictates the best exposure option as severe patella baja may not be overcome with a proximally based release. The quadriceps snip is most commonly used and provides improved exposure without the necessity of modifying the patient's post-operative rehabilitation. In addition, it can be extended to a quadriceps turndown which vastly improves visualization, but at the expense of needing to immobilise the knee post-operatively. A tibial tubercle osteotomy can also be used and provides excellent exposure especially in the case of severe patella baja or when removal of a cemented tibial stem is required. It preserves the extensor muscles, but risks include increased post-operative wound drainage due to limited soft tissue coverage, failure of fixation, or fracture of the tibial tubercle fragment or tibial shaft. Exposure in revision total knee arthroplasty is critical. Fortunately, this can be reliably achieved with a systematic approach to the knee and through the use of several extensile exposures at the surgeon's discretion

Revision total knee arthroplasty (TKA) can pose significant challenges. Successful reconstruction requires a systematic approach with the ultimate goal being a well fixed and balanced knee prosthesis. Careful preoperative planning is necessary for safe exposure, component removal, and appropriate management of bone loss during revision knee surgery. Prior to surgery, the cause of failure must be understood. Revision TKA without a clear diagnosis has been shown to lead to predictable poor results. A careful history and physical examination for both intrinsic and extrinsic causes of knee pain need to be performed. An ESR and C-reactive protein should be obtained in every patient with a painful TKA and in cases of serologic abnormalities, a joint aspiration performed. The integrity of the collateral ligaments and the degree of anticipated bone loss at the time of revision needs to be established. In cases of severe collateral ligament deficiency, the need for constrained or hinged knee implants should be anticipated. Plain radiographs are needed to evaluate present component position, loosening, and osteolysis. Oblique radiographs and advanced imaging (i.e. CT or MRI) have been shown to more accurately quantify the severity of lysis compared to standard radiographs. This careful assessment can help prepare for the need of special implants, stems, wedges, or augments. Finally, patient risk stratification and medical co-management can help minimise complications following revision TKA. Optimization of potentially modifiable risk factors such as glycemic control, BMI, and preoperative hemoglobin can reduce perioperative morbidity and complications

Joint assessment through manual physical examination is a fundamental skill that must be acquired by orthopaedic surgeons. These joint assessments allow surgeons to identify soft tissue injuries (e.g. ligament tears) which are critical in identifying appropriate treatment options. The difficulty in communicating the feeling of different joint conditions and the limited opportunities for practice can make these skills challenging to learn, resulting in reduced treatment effectiveness and increased costs. This research seeks to improve the training of joint assessment with the creation of a haptic joint simulator that can train surgeons with increased effectiveness. A first of its kind haptic simulator is presented, which incorporates: a newly defined kinetic knee simulation, a haptic device for user interaction, and a haptic control algorithm. The knee model has been specifically created for this application and allows six degree-of-freedom manipulation of the tibia while considering the effects of ten knee ligament bundles. The model has been mathematically formulated to allow for the high update rates necessary for smooth and stable haptic simulation. Two quantitative assessments were made of the model to confirm its clinical validity. The first was against the widely used OpenSim biomechanical simulation software. Simulations of the model's performance for both anterior-posterior draw tests and varus-valgus rotation tests showed less than 0.7%RMSE for force and 5.5%RMSE for moments. Crucially, the proposed model could generate updated forces in less than 1ms, compared to 188ms for OpenSim. The second validation of the model was against a cadaveric knee that was tested using a validated robotic testing platform. This comparison showed that the model could generate similar force- motion pathways to the cadaveric knee after the model's parameters were scaled to match. Having demonstrated that it is possible to create a computational knee model that has good conformance to gold-standard knee simulations and cadaveric recordings, while updating at less than 1ms, this research has overcome a major hurdle. The next stage of this research will be to incorporate the knee model into a full haptic simulator and perform skill acquisition trials. Given the effectiveness of past haptic training systems in aiding clinical skills acquisition, this research offers a promising way to improve surgeon training, and therefore also patient diagnosis and treatment

The contemporary metal-on-metal (MoM) bearings were reintroduced due to their lower volumetric wear rates in comparison to conventional metal-on-polyethylene bearings. This has the potential to substantially reduce wear-induced osteolysis as the major cause of failure and greater implant stability with the use of large femoral heads. It has been estimated that since 1996 more than 1,000,000 MoM articular couples have been implanted worldwide. However, with increasing clinical experience, the national joint registries have recently reported the failure rate of THA with MoM bearings to be 2–3 fold higher than contemporary THA with non-metal-on-metal bearings. Moreover, adverse periprosthetic tissue reactions have emerged as an important reason for failure in MoM patients. A painful MoM hip arthroplasty has various intrinsic and extrinsic causes. As in all painful THA, a thorough clinical history, a detailed physical examination, as well as radiographic and laboratory tests are essential to delineate potential cause(s) of pain in patients with MoM hip arthroplasty. While specialised tests such as metal ion analysis are useful modalities for assessing MoM hip arthroplasty, over-reliance on any single investigative tool in the clinical decision-making process should be avoided. There should be a low threshold to perform a systematic evaluation of patients with MoM hip arthroplasty as early recognition and diagnosis will facilitate the initiation of appropriate treatment prior to significant adverse biological reactions. A systematic risk stratification recommendation, for multiple modes of failure including adverse local tissue reactions, based on the currently available evidence will be presented to optimise management

Bone localization of tuberculosis mainly affects the thoracolumbar spine. The cervical spine is rare. Its diagnosis is often late which exposes to great instability and potentially serious complications. We reported the case of a patient with cervical spine tuberculosis with a rare localisation. A 10-years old boy with no medical history, showed torticolis and high temperature without neurological complication. In the physical examination, he had torticolis and pain in the third, forth and fifth cervical vertebra. The biology showed high CRP 200mg/l. The tomodensitometry of the cervical spine showed a collection of the third cervical spine. The patient took non specific Antibiotics for two months with no radiological improvement. When biopsy was performed, we find an inter apophysis (between C3 and C4) collection. The histological examination confirmed the diagnosis of apophysis tuberculosis. The cervical spine is a rare localisation of the tuberculosis. The apophysis localisation is a more uncommon localisation. The diagnosis is difficult. The histological examination is essential for the diagnosis. The management based on tuberculosis chemotherapy and immobilization started as soon as possible