Objectives. Our aim was to assess the use of intra-operative fluoroscopy in the assessment of the position of the tibial tunnel during reconstruction of the anterior cruciate ligament (ACL). Methods. Between January and June 2009 a total of 31 arthroscopic hamstring ACL reconstructions were performed. Intra-operative fluoroscopy was introduced (when available) to verify the position of the guidewire before tunnel reaming. It was only available for use in 20 cases, due to other demands on the radiology department. The tourniquet times were compared between the two groups and all cases where radiological images lead to re-positioning of the guide wire were recorded. The secondary outcome involved assessing the tibial interference screw position measured on post-operative radiographs and comparing with the known tunnel position as shown on intra-operative fluoroscopic images. Results. Of the 20 patients treated with fluoroscopy, the imaging led to repositioning of the tibial guide wire before reaming in three (15%). The mean tourniquet time with intra-operative fluoroscopy was 56 minutes (44 to 70) compared with 51 minutes (42 to 67) for the operations performed without. Six patients (30%) had post-operative screw positions that were > 5% more posterior than the known position of the tibial tunnel. Conclusion. Intra-operative fluoroscopy can be effectively used to improve the accuracy of tibial tunnel positions with minimal increase in tourniquet time. This study also demonstrates the potential inaccuracy associated with plain radiological assessment of tunnel position

Aims. The aims of this study were to examine the rate at which the positioning of the acetabular component, leg length discrepancy and femoral offset are outside an acceptable range in total hip arthroplasties (THAs) which either do or do not involve the use of intra-operative digital imaging. Patients and Methods. A retrospective case-control study was undertaken with 50 patients before and 50 patients after the integration of an intra-operative digital imaging system in THA. The demographics of the two groups were comparable for body mass index, age, laterality and the indication for surgery. The digital imaging group had more men than the group without. Surgical data and radiographic parameters, including the inclination and anteversion of the acetabular component, leg length discrepancy, and the difference in femoral offset compared with the contralateral hip were collected and compared, as well as the incidence of altering the position of a component based on the intra-operative image. Results. Digital imaging took a mean of five minutes (2.3 to 14.6) to perform. Intra-operative changes with the use of digital imaging were made for 43 patients (86%), most commonly to adjust leg length and femoral offset. There was a decrease in the incidence of outliers when using intra-operative imaging compared with not using it in regard to leg length discrepancy (20% versus 52%, p = 0.001) and femoral offset inequality (18% versus 44%, p = 0.004). There was also a difference in the incidence of outliers in acetabular inclination (0% versus 7%, p = 0.023) and version (0% versus 4%, p = 0.114) compared with historical results of a high-volume surgeon at the same centre. Conclusion. The use of intra-operative digital imaging in THA improves the accuracy of the positioning of the components at THA without adding a substantial amount of time to the operation. Cite this article: Bone Joint J 2018;100B(1 Supple A):36–43

Intra-operative complications vary from extremely benign such as glenoid vault penetration to life and limb threatening for example brachial artery injury. Most intra-operative complications can be avoided with careful pre-operative planning, anticipation, and execution. However, even the best planning and execution including fluoroscopic guided reaming cannot prevent all complications. The following intra-operative complications will be discussed in detail in regards to both prevention and management: Glenoid vault penetration, Glenoid component malposition - reverse and primary, Glenoid fracture - reverse and primary, Humeral component malposition - reverse and primary, and Humeral fracture - reverse and primary

Intra-operative fractures of the femur are on the rise mainly due to the increased use of cementless implants and the desire to get a tight pressfit. The prevalence has been reported to be between 1–5% in cementless total hip arthroplasties (THAs). The key to preventing these fractures is to identify patients at high risk and careful surgical technique. Surgical risk factors include the use of cementless devices, revision hip surgery, the use of flat tapered wedges and MIS surgery. Patient factors that increased risk include increasing age, female gender, osteopenia and rheumatoid arthritis. These risk factors tend to be additive and certainly when more than one is present extra caution needs to be taken. Surgical technique is critical to avoid these intra-operative fractures. Fractures can occur during exposure and dislocation, during implant removal (in revision THA), during canal preparation and most commonly during stem insertion. In both primary and especially in revision THA, be wary of the stiff hip in association with osteopenia or osteolysis. These patients require a very gentle dislocation. If this cannot be achieved, then alteration of the standard approach and dislocation may be needed. Examples of these include protrusion with an osteopenic femur and revision THA with a very stiff hip with lysis in the femur. Lastly, in cases with retained hardware, dislocate prior to removing plates and screws. After dislocation, the next challenge is gentle preparation of the femoral canal. A reasonable exposure is required to access the femoral canal safely. MIS procedures do not offer as good access to femoral canal and this probably results in increased risk of fracture during broaching or implant insertion. When broaching, stop when broach will not advance further. When inserting a tapered wedge stem, be worried if stem goes further in than broach. In revision surgery when taking the stem out from above, make sure the greater trochanter does not overhang the canal. A high speed burr can clear the shoulder for easier access for removal. In revision THA with an ETO place a cerclage wire prior to reaming and retighten prior to stem insertion. Even with careful surgical technique intra-operative femoral fractures will still occur. When inserting the stem a sudden change in resistance is highly suggestive of fracture. Wide exposure of the entire proximal femur is necessary to confirm the diagnosis. The distal extent of the fracture must be seen. Only on occasion is an intra-operative radiograph needed. Management is directed to ensuring component stability and good fracture fixation. In primary total hip arthroplasty calcar fractures are by far the most common. If using proximal fixation and you are certain the stem is stable, then all that is needed is cerclage wiring. As already mentioned, you must follow the fracture line distally so you are aware of how far down it goes. Often what appears to be a calcar split actually propagates distal to the lesser trochanter. In these cases, one would probably go for distal fixation plus wiring. In conclusion intra-operative femoral fractures are on the rise. Prevention is the key. If a fracture, exposure is the key to deciding on a treatment plan

Two critical steps in achieving optimal results and minimizing complications (dislocation, lengthening, and intra-operative fracture) are careful pre-operative planning and more recently, the option of intra-operative imaging in order to optimise accurate and reproducible total hip replacement. The important issues to ascertain are relative limb length, offset and center of rotation. It is important to start the case knowing the patient's perception of their limb length. Patient perception is equally important, if not more important, than the radiographic assessment. On the acetabular side, the teardrop should be identified and the amount of reaming necessary to place the inferior margin of the acetabular component adjacent to the tear drop should be noted. Superiorly the amount of exposed metal that is expected to be seen during surgery should be measured in millimeters. Once the key issues of limb length, offset, center of rotation, and acetabular component position relative to the native acetabulum have been confirmed along with the expected sizing of the acetabular and femoral components, it is critical that the operative plan is reproduced at the time of surgery and this can best be consistently performed with the use of intra-operative imaging. Advances in digital imaging now make efficient, cost-effective assessment of hip replacement possible. Embedded software allows accurate confirmation of the pre-operative plan intra-operatively when correction of potential errors is easily possible. Such technology is now mature after years of clinical use and studies have confirmed its success in avoiding outliers and achieving optimal results

Clinical nerve injury has been reported in 0.6–4.8% of shoulder arthroplasties. Classical teaching is that 70–85% of injuries recover. Despite recovery of motor function, overall shoulder function may be negatively affected and residual pain is common. Complex regional pain syndromes may develop and become permanent. Consequently, methods to limit nerve injury have been investigated. In the early 2000's I became concerned about the incidence of nerve injuries in my arthroplasty practice. I became intrigued with the idea of peripheral nerve monitoring as a method to alert the surgeon intra-operatively about impending nerve insults so that evasive measures could be taken to prevent any clinically significant nerve injuries. The results of our first 30 consecutive patients were published in JSES in 2007. Seventeen patients (56.7%) had 30 episodes of nerve dysfunction (i.e. nerve alerts) during surgery. Twenty-three of thirty alerts (76.7%) returned to normal after repositioning the arm to a neutral position. Post-operative EMG was positive in 4 of 7 (57.1%) patients who did not have a return to normal motor latency intra-operatively and in 1 of 10 (10%) patients whose intra-operative nerve function did return to normal. None had clinical nerve injuries. This early experience indicated that nerve injury was potentially more common than previously thought but intra-operative nerve monitoring seemed to have a relatively high false positive rate. Our group subsequently studied 440 shoulder arthroplasty cases. The protocol used to identify a nerve alert was made more restrictive than the first study as an attempt to decrease the false positive rate. In this larger group, nerve alerts occurred in 185 cases (42.0%), and 37 (8.4%) cases did not have signals return to above the alert threshold at closure. There were no permanent post-operative nerve injuries and 5 transient nerve injuries (1.1%). Cases in which MEP amplitudes remained below alert threshold were significantly more likely to have a post-operative nerve injury (p = 0.03). There were no false negatives, (i.e. a post-operative nerve injury occurred while MEPs were normal at closure), making sensitivity 100%. There were 32 false positives, leading to a specificity of 92.6%, a positive predictive value (PPV) of 13.5%, a negative predictive value (NPV) of 100%, and an accuracy (ACC) of 92.3%. In my opinion, the high false positive rate and the low PPV make the technique difficult to justify for routine clinical use

Aim. Whether pre-operative microbiological sampling contributes to the management of chronic peri-prosthetic infection remains controversial. We assessed agreement between the results of pre-operative and intra-operative samples in patients undergoing single-stage prosthesis exchange to treat chronic peri-prosthetic infection. The tested hypothesis was that agreement between pre-operative and intra-operative samples exceeds 75% in patients undergoing single-stage exchange of a hip or knee prosthesis to treat chronic peri-prosthetic infection. Method. This single-centre retrospective study included 85 single-stage prosthesis exchange procedures in 82 patients with chronic peri-prosthetic infection at the hip or knee. Agreement between pre-operative and intra-operative sample results was evaluated. Changes to the initial antibiotic regimen made based on the intra-operative sample results were recorded. Associations between sample agreement and infection-free survival were assessed. Results. Of 149 pre-operative samples, 109 yielded positive cultures, in 75/85 cases. Of 458 intra-operative samples, 354 yielded positive cultures, in 85/85 cases. Agreement was complete in 54 (63%) cases and partial in 9 (11%) cases; there was no agreement in the remaining 22 (26%) cases. The complete agreement rate was significantly lower than 75% (p=0.01). The initial antibiotic regimen was inadequate in a single case. Agreement between pre-operative and intra-operative samples was not significantly associated with infection-free survival. Conclusions. Pre-operative sampling may contribute to the diagnosis of peri-prosthetic infection but is neither necessary nor sufficient to confirm the diagnosis and identify the causative agent. The spectrum of the initial antibiotic regimen cannot be safely narrowed based on the pre-operative sample results. We suggest the routine prescription of a probabilistic broad-spectrum antibiotic regimen immediately after the prosthesis exchange, even when a pathogen was identified before surgery. No funding from any part was received for the purpose of this study

Introduction. Recent advances in 3D printing enable the use of custom patient-specific instruments to place drill guides and cutting slots for knee replacement surgery. However, such techniques limit the ability to intra-operatively adjust an implant plan based on soft-tissue tension and/or joint pathology observed in the operating room, e.g. cruciate ligament integrity. It is hypothesized that given the opportunity, a skilled surgeon will make intra-operative adjustments based on intra-operative information not captured by the hard tissue anatomy reconstructed from a pre-operative CT scan or standing x-ray. For example, tibiofemoral implant gaps measured intra-operatively are an indication of soft-tissue tension in the patient's knee, and may influence a surgeon to adjust implant position, orientation or size. This study investigates the frequency and magnitude of intra-operative adjustments from a single orthopedic surgeon during 38 unicondylar knee arthroplasty (UKA) cases. Methods. For each patient, a pre-operative plan was created based on the bony anatomy reconstructed from the pre-operative CT. This plan is analogous to a plan created with patient-specific cutting blocks or customized implants. With robotic technology that utilizes pre-operative imaging, intra-operative navigation and robotic execution, this “anatomic” plan can be fine-tuned and adjusted based on the soft tissue envelop measured intra-operatively. The relative positions of the femur and the tibia are measured intra-operatively under a valgus load (for medial UKA, varus load for lateral UKA) for each patient from extension to deep knee flexion and used to compute the predicted space between the implants (gaps) throughout flexion. The planned position, orientation and size of the components can then be adjusted to achieve an optimal dynamic ligament balance prior to any bony cuts. This is the plan that is then executed under robotic guidance. Intra-operative adjustments are defined as any size, position or orientation changes occurring intra-operatively to the pre-operative anatomic plan. Results. The surgeon adjusted the pre-operative implant plan in 86.8% of cases, leading to combined RMS changes of 2.0 mm and 2.1 degrees to the femoral implant, and 0.9 mm and 1.4 degrees to the tibial implant. The RMS femoral implant translations and rotations were 1.0, 1.5, 0.9 mm and 1.0, 1.0, 1.7 degrees in the medial, anterior, and superior directions, respectively. The RMS tibial implant translations and rotations were 0.2, 0.4, 0.8 mm and 1.3, 0.4, 0.6 degrees in the medial, anterior, and superior directions, respectively. Implant sizes were adjusted in 36.8% of cases, with all changes occuring to the femoral implant, and 13 out of those 14 cases showing a reduction in the femoral implant size. Conclusions. These data support the hypothesis that surgical planning of UKA components based on accurate 3D dimensional reconstructions of anatomy alone is not adequate to create optimal implant gap spacing throughout flexion. Measurement and knowledge of the patient's soft tissue envelope allows for signficiant changes to the implant plan prior to any bony cuts

Controversy remains regarding the optimal treatment for iatrogenic injury to the medial collateral ligament (MCL) during primary total knee arthroplasty (TKA). Some authors have recommended converting to a prosthesis that provides varus/valgus constraint while others have recommended primary repair. In this study we report the results of a 45 patients who sustained intra-operative MCL injuries during primary TKA that were treated with primary repair. Of 3922 consecutive primary TKA there were 48 (1.2%) intra-operative MCL lacerations or avulsions. One patient was lost and one died before 24-month follow-up. All but one patient underwent primary repair with placement of components without varus/valgus constraint. This left 45 knees with a mean follow up of 89 months (range, 24 – 214 months). The mean HSS knee scores increased from 47 to 85 points (p<0.001). No patients had subjective complaints of instability. No patients had excessive varus/valgus laxity when tested in full extension and 30 degrees of flexion. The range of motion at the time of final follow-up averaged 110 degrees (range, 85 – 130 degrees). Five knees required treatment for stiffness with 4 knees undergoing manipulation under anesthesia and 1 knee undergoing open lysis of adhesions with polyethylene articular surface exchange. Two knees underwent revision for aseptic loosening of the tibial component. In the three knees that underwent open revision, the MCL was noted to be in continuity and without laxity. Primary repair with 6 weeks of post-operative hinged bracing after iatrogenic injury to the MCL during primary TKA was successful at preventing instability although stiffness was seen in approximately 10% of patients. The increased morbidity associated with implantation of a semi-constrained or constrained implant may be unwarranted in this situation

A concern with diaphyseal-fitting cementless stems in revision total hip arthroplasty is intra-operative fractures. Two hundred and eleven patients consecutively underwent revision hip arthroplasty using Solution stems (DePuy, Warsaw, IN). Intra-operative fractures or perforations occurred in sixty-four patients (30% prevalence), with diaphyseal splits in thirty-nine patients (18% prevalence). Risk factors were pre-operative osteolysis, cortex to canal ratio, under-reaming the cortex and large diameter stems. The majority of diaphyseal linear cracks occurred at the distal end of extended trochanteric osteotomies during stem insertion. Intra-operative fracture is associated with an average two days longer length of stay (p< 0.05). The purpose of this study was to determine the identification of the risk factors and outcomes of intra-operative fractures using a diaphyseal fitting revision stem. There is an association of intra-operative fracture associated using a diaphyseal-fitting stem in revision total hip arthroplasty with a longer length of stay in hospital. Identifying preoperative risk factors will allow avoidance of such fractures and prolonged hospital stay. Intra-operative fractures or perforations occurred in sixty-four patients (30% prevalence) and thirty-nine patients (18% prevalence) sustained diaphyseal splits. Risk factors associated with intra-operative fracture were pre-operative osteolysis, a low cortex to canal ratio, under-reaming the cortex and the use of a large diameter stem. Surgical approach was not directly related to fracture occurrence but the majority of diaphyseal undisplaced linear cracks occurred at the distal end of extended trochanteric osteotomies during stem insertion. Cortical perforation occurred most often with cement removal. Duration of stay was on average two days longer (p< 0.05) for patients with an intraoperative fracture. Two hundred and eleven patients who had undergone revision hip arthroplasty using the Solution stem (DePuy, Warsaw, IN) between December 1998 and March 2002 were identified. Patients who sustained an intra-operative fracture were compared to controls patients who underwent hip revision at the same time frame but with no fracture. Multiple factors were analyzed to see which were risk factors for intra-operative fractures. There is a surprisingly high incidence of intra-operative fracture associated with using a diaphyseal-fitting stem in revision total hip arthroplasty. This was associated with a longer length of stay

Introduction. The aim of this study is to verify the intra-rater and inter-rater reliability of intra-operative kinematics by hand in TKA using a computer assisted image-free navigation system. Material and Methods. Total knee arthroplasty (TKA) was performed on the knees of twelve (12) patients with knee navigation by one surgeon. Patients were divided into two groups: Group A included six knees that were operated on with assistant A (senior joint surgeon); and Group B included the other six knees that were operated on with assistant B (resident). For each knee, axial rotation was evaluated three times by the operator and the assistant using a navigation system at 30°, 60°, 90°, 120° passive flexions by hand. Intra-class correlation coefficients (ICC) were calculated for each evaluation to examine intra-rater and inter-rater reliability. Results. As intra-rater reliability, ICC (1,1) of the operator were 0.965 (range: 0.951 to 0.978); assistant A were 0.949 (range: 0.898 to 0.974); and assistant B were 0.987 (range: 0.982 to 0.992). As inter-rater reliability, ICC (2,1) of the operator and assistant A were 0.947 (range: 0.937 to 0.975), while the operator and assistant B were 0.949 (range: 0.887 to 0.989). The results demonstrated almost perfect reliability (ICC>0.81) of the inter-examiner and intra-examiner in each knee flexion angle. Conclusion. Intra-operative kinematic analysis by hand using a knee navigation system showed almost perfect reliability of not only the intra-examiner but also the inter-examiner. This result indicates that intra-operative kinematic analysis is useful information to be referred

Introduction. Total knee arthroplasty (TKA) using conventional instrumentation has been shown to be a safe and effective way of treating end stage osteoarthritis by restoring function and alleviating pain. As robotic technology is developed to assist surgeons with intra-operative decision making such as joint balancing and component positioning, the safety of these advancements must be established. Furthermore, functional recovery and clinical outcomes should achieve comparable results to the gold standard of conventional instrumentation TKA. Methods. Eighty-seven subjects (89 knees) underwent robotic arm assisted TKA by one of three investigators as part of an FDA and IRB approved Investigational Device Exemption (IDE). To achieve the primary endpoint of intra-operative patient safety using a robotic arm assisted cutting tool, the investigators completed questionnaires to assess a series of complications related to soft tissue damage associated with conventional TKA. Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Knee Society Knee Scores (KSS) were collected pre-operatively and at three month follow-up. Results. The average subject age was 65.8 ± 8.5 and the average BMI was 31.4 ± 5.7. 55% of the subjects were female. No subject experienced any of the rare intra-operative complications that comprise the primary safety endpoint. The average WOMAC score improvement from pre-operative to three months was 33.1 ± 20.04 (p<0.0001). The average KSS Knee score improvement was 46.1 ± 19.7 (p<0.0001). Subjects recovered their pre-operative range of motion by three months post-operative. Conclusion. Results from this prospective robotic arm assisted trial indicated greater intra-operative safety in blood loss and ligamentous damage when compared to conventional TKA. Subjects had excellent return to function and pain relief by three months as indicated by the KSS and WOMAC scores. Robotic technologies should be considered a safe and effective method in total joint restoration

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

Revision total hip replacement is often associated with significant blood loss and subsequent transfusion. Intra-operative cell salvage is one approach to minimising this allogenic transfusion. We carried out a retrospective study of 158 consecutive revision THRs carried out by one surgeon between June 2003 and September 2006 in the Southern General Hospital, Glasgow. In the study group (79 patients, operated upon after October 2005) Intra-operative cell salvage was routinely used for all cases. In the control group (79 patients, operated upon before October 2005) Intra-operative cell salvage was not available. Data was collected on transfusion of salvaged blood, transfusion of allogenic blood, operation type, indication for surgery, complications and length of hospital stay. Results showed a 53% reduction (p=0.002) in the number of units of allogenic blood transfused in the study group compared with the control group. (1.59 units per case compared with 3.41 units). In the study group 51% of patients received allogenic blood transfusion, compared with 68% of patients in the control group, a relative reduction of 17% (p=0.02). There was no difference between the two groups regarding haemoglobin drop and length of hospital stay. Data regarding complications yielded no significant results due to small cohort size. We conclude that intra-operative cell salvage leads to a significant reduction in allogenic blood transfusion with subsequent implications upon cost, resource management, and patient safety and should be used for all patients undergoing revision hip arthroplasty

The recent introduction of digital radiography has enabled a paradigm shift in intra-operative imaging technology. Rather than deal with the cumbersome process of chemical image processing we can now acquire a high quality digital image in a matter of seconds. The functionality approaches that of fluoroscopy, or even a C-arm, however, a digital system can operate with lower radiation, higher resolution, and perhaps most importantly a larger field of view. These features and the greater ability for post-acquisition, digital image enhancement make it very suitable for use during surgery. The purpose of this presentation is to illustrate the intra-operative technique and share the overwhelmingly positive experience gathered over the past few years. The current paradigm in total hip arthroplasty (THA) employs use of post-operative radiography for “outcome assessment.” This unfortunately does not allow the surgeon to evaluate the relevant parameters and make necessary adjustments without returning to the operating room. The new paradigm, however, permits intra-operative guidance and “outcome control.” We now have an opportunity to add a “trial radiograph” to our practice of performing a trial reduction. This provides an immediate and complete preview of what the post-operative film will show. There is now an opportunity, during the course of any hip arthroplasty, to optimise component orientation, sizing, apposition, screw position, limb length, and offset, before leaving the operating room. This can be done with minimal intrusion on normal workflow, adding only a few minutes of operating time

Revision total hip replacement is a procedure often associated with significant blood loss and subsequent transfusion. Intra-operative cell salvage is one approach to minimising this problem. We carried out a retrospective study of 134 consecutive revision total hip carried out by one surgeon between June 2003 and September 2006 in the Southern General Hospital, Glasgow, 134 replacements (excluding those performed in the presence of active infection where cell salvage is contra-indicated). In Group A (56 patients), operated upon after October 2005, Intra-operative cell salvage was routinely used. In Group B (78 patients), operated upon before October 2005, Intra-operative cell salvage was not used. Data was collected on transfusion of salvaged blood, transfusion of allogenic blood, operation type, indication for surgery, complications and length of hospital stay. In Group A, an average of 1.52 units of allogenic blood was transfused per case, compared with an average of 3.35 units in Group B (p=0.01), a reduction of 55%. In Group A 50% of patients received allogenic blood transfusion, compared with 68% of patients in Group B, a relative reduction of 26% (0.1> p> 0.05). There was no difference between the two groups regarding haemoglobin drop and length of hospital stay. Data regarding complications yielded no significant results due to small cohort size. Further Breakdown of data by operation type and indication did not yield significant results due to the small cohort size. Our results show that routine use of intra-operative cell salvage in revision total hip replacement leads to a significant reduction in allogenic blood transfusion with subsequent implications upon cost, resource management, and patient safety

To analyse the intra-operative variation in mechanical axes of the lower limb at various stages during navigated total knee replacement. A prospective study was performed to analyse the intra-operative variation in the mechanical axes of the lower limb during navigated total knee replacement. All consecutive patients who underwent navigated total knee replacement were included and patients with inadequate data were excluded from the study. The intra-operative initial, trial and the final mechanical hip-knee-ankle axes were recorded from the navigation system. The differences between these axes were calculated and analysed. There were forty patients, of which 24 were females and 16 males with the age ranging from 37-89 (average 68.4) years. The right knee was replaced in 27 and the left knee in 13 patients. The average initial mechanical axes alignment was 0.03° valgus (3° varus to 3° valgus), trial alignment 0.64° varus (3° varus to 1.5° valgus) and final alignment 0.25° varus (4° varus to 4° valgus). Average deviation from initial to trial axes was 0.97°, trial to final axes was 0.74° and initial to final axes was 1.08°. The correlation co-efficient between the initial and the trial axes was 0.25, trial and final axes was 0.43 & initial and final axes was 0.09. This study highlights a significant variation in mechanical axes between the different stages of navigated total knee replacement. The potential sources of intra-operative errors causing these changes could be soft tissue imbalance, variations in implant placement and possible tracker micro motion. Execution of bony cuts in near normal neutral alignment does not guarantee achievement of near normal final alignment. We advocate surgeons to be vigilant to avoid potential malalignment during navigated total knee replacement

Backgrounds. In order to permit soft tissue balancing under more physiological conditions during total knee arthroplasties (TKAs), we developed an offset type tensor to obtain soft tissue balancing throughout the range of motion with reduced patella-femoral (PF) and aligned tibiofemoral joints and reported the intra-operative soft tissue balance assessment in cruciate-retaining (CR) and posterior-stabilized (PS) TKA [1, 2]. However, the soft tissue balance in unicompartmental knee arthroplasty (UKA) is unclear. Therefore, we recently developed a new tensor for UKAs that is designed to assist with soft tissue balancing throughout the full range of motion. The first purpose of the present study is to assess joint gap kinematics in UKA. Secondly, we attempted to compare the pattern in UKA with those in CR and PS TKA with the reduced PF joint and femoral component placement, which more closely reproduces post-operative joint alignment. Methods. Using this tensor, we assessed the intra-operative joint gap measurements of UKAs performed at 0, 10, 30, 45, 60, 90, 120 and 135° of flexion in 20 osteoarthritic patients. In addition, the kinematic pattern of UKA was compared with those of CR and PS TKA that were calculated as medial compartment gap from the previous series of this study. Results. While the joint gap measurements of UKAs increased from full extension to extension (10 degrees of flexion), these values remained constant throughout the full range of motion. Of note, the gap values of CR TKA were significantly smaller from midrange to deep flexion compared with PS TKA, and furthermore UKA showed a significantly smaller gap from extension to midrange flexion compared with CR TKA. Conclusions. Accordingly, we conclude that the intra-operative joint gap kinematic pattern in UKA differs from the pattern in TKA

Controversy remains regarding the optimal treatment for iatrogenic injury to the medial collateral ligament (MCL) during primary total knee arthroplasty (TKA). Some authors have recommended converting to a prosthesis that provides varus/valgus constraint while others have recommended primary repair. In this study, we report the results of 45 patients who sustained intra-operative MCL injuries during primary TKA that were treated with primary repair. Of 3922 consecutive primary TKA there were 48 (1.2%) intra-operative MCL lacerations or avulsions. One patient was lost and one died before 24 months follow up. All but one patient underwent primary repair with placement of components without varus/valgus constraint. This left 45 knees with a mean follow up of 89 months (range, 24 to 214 months). The mean HSS knee scores increased from 47 to 85 points (p<0.001). No patients had subjective complaints of instability. No patients had excessive varus/valgus laxity when tested in full extension and 30 degrees of flexion. The range of motion at the time of final follow-up averaged 110 degrees (range, 85 to 130 degrees). Five knees required treatment for stiffness with 4 knees undergoing manipulation under anaesthesia and 1 knee undergoing open lysis of adhesions with polyethylene articular surface exchange. Two knees underwent revision for aseptic loosening of the tibial component. In the three knees that underwent open revision, the MCL was noted to be in continuity and without laxity. Primary repair with 6 weeks of post-operative hinged bracing after iatrogenic injury to the MCL during primary TKA was successful at preventing instability although stiffness was seen in approximately 10% of patients. The increased morbidity associated with implantation of a semi-constrained or constrained implant may be unwarranted in this situation

Background. Component positioning in total hip arthroplasty (THA) is critical to achieve optimal patient outcomes. Recent literature has shown acetabular component positioning may be inaccurate using traditional techniques. Robotic-assisted THA is a recent platform introduced to decrease the risk of malpositioned components. However, to date, a paucity of data is available comparing the intra-operative component position generated by the navigation system to post-operative radiographs. Purpose. The purpose of this study was to compare the component position measurements of a navigation system, used during robotic-assisted THA, to component position measurements obtained on post-operative radiographs. Methods. Intra-operative component position measurements for acetabular inclination, acetabular anteversion, leg length change, and offset change for 145 patients were recorded. Pre-operative and post-operative radiographs of the same 145 patients were then measured for the same parameters. A comparison of component position provided by the navigation system and radiographic data was then performed. Sub-group analyses of posterior and direct anterior measurements were performed. Results. Correlation between the navigation system and post operative radiographs was within 10° for 95.9% of cases for inclination and 96.6% for anteversion. Correlation within 10 mm of radiographic-measured values occurred in 97.7% of cases for change in leg length and 94.0% for change in global offset. 100% of the cases ended up with radiographic leg length discrepancy of less than 10 mm. Conclusion. The intra-operative component position data obtained from the navigation system utilized during robotic-assisted THA demonstrated correlated well with component position data obtained from radiographs