Purpose. Introduce an Integrated Approach for Orthopedic-Sports Medicine Practice and Patient Care Management that. Is built around effective and efficient surgical techniques, and patient care management processes. Integrates Operations and Service Excellence best practices with patient care management processes. Integrates orthopedic care delivery between outpatient clinic, pre-surgery, surgery, inpatient, (acute care) and post acute care settings. Delivers exceptional clinical, patient satisfaction and financial outcomes as validated by independent national healthcare benchmarking organization. Helps position Ortho-Sports medicine services for strategic growth. Is replicable to develop Ortho-Sports Medicine Centers of Excellence. Presentation illustrates the ‘Ten Elements’ approach to implement the Ortho-Sports Medicine Centers of Excellence and demonstrate the effectiveness of the approach with an outcomes study from over 1000 total knee arthroplasty (TKA) procedures. During the presentation, the speakers would share the key clinical, patient satisfaction, and financial outcomes achieved by the implementation of the best practices defined in our ‘Ten Elements’ approach. All performance data elements are collected, validated and analyzed by an independent third party, national healthcare benchmarking company. During the presentation Dr. Bramlett would elaborate on the surgical protocol, and the key differentiating steps in procedure technique from traditional approach that significantly enhances procedure effectiveness, efficiency and lowers the patient complication rate as demonstrated by benchmarking data. Speakers would further present the key elements of Total Knee Arthoplasty procedure that focus on patient education, patient participation in pre-surgical weight loss and pre-habilitation program, anesthesia approach, avoiding tourniquet use and deep veen thrombosis (DVT) risk reduction, early post operative patient ambulation and weight bearing, and post operative patient management approach. On average the ortho-sports medicine clinical of Alabama TKA patients are disharged from the hospital in 2.6 days, and experience 65 percent less complications than expected for a similar patient population and assume early control of their independent functionality

Introduction

In total knee arthroplasty, the aim is to relieve pain and provide a stable, functional knee. Sagittal stability is crucial in enabling a patient to return to functional activities. Knee implants with a medial pivot (MP) design are thought to more accurately reproduce the mechanics of the native joint, and potentially confer greater antero-posterior stability through the range of flexion than some other implant designs.

Tranexamic Acid (TA) has been shown to reduce transfusion rates in Total Knee Replacement (TKR) without complication. In our unit it was added to our routine enhanced recovery protocol. No other changes were made to the protocol at this time and as such we sought to examine the effects of TA on wound complication and transfusion rate.

All patients undergoing primary TKR over a 12 month period were identified. Notes and online records were reviewed to collate demographics, length of stay, use of TA, thromboprophylaxis, blood transfusion, wound complications and haemoglobin levels. All patients received a Columbus navigated TKR with a tourniquet. Only patients who received 14 days of Dalteparin for thromboprophylaxis were included.

124 patients were included, 72 receiving TA and 52 not. Mean age was 70. Four patients required a blood transfusion all of whom did not receive TA (p = 0.029). Mean change in Hb was 22 without TA and 21 with (p = 0.859). Mean length of stay was 6.83 days without Tranexamic Acid and 5.15 with (p < 0.001). 15% of patients (n=11) of the TA group had a wound complication, with 40% of patients (n=21) in the non TA group (p = 0.003). There was one ultrasound confirmed DVT (non TA group). No patients were diagnosed with pulmonary embolus.

In our unit we have demonstrated a significantly lower transfusion rate, wound complication rate and length of stay, without any significant increase in thromboembolic disease with the use of TA in TKR.

To date, there are no clear guidelines from the National Institute of Clinical Excellence or the British Orthopaedic Association regarding the use of Autologous Blood Transfusion (ABT) drains after elective primary Total Knee Replacement (TKR). There is little evidence to comparing specifically the use of ABT drains versus no drain. The majority of local practice is based on current evidence and personal surgical experience.

We aim to assess whether the use of ABT drains effects the haemoglobin level at day 1 post-operation and thus alter the requirement for allogenic blood transfusion. In addition we aim to establish whether ABT drains reduce post-operative infection risk and length of hospital stay.

Forty-two patients undergoing elective primary TKR in West London between September 2011 and December 2011 were evaluated pre- and post-operatively. Patient records were scrutinised. The patient population was divided into those who received no drain post-operatively and those with an ABT drain where fluid was suctioned out of the knee in a closed system, filtered in a separate compartment and re-transfused into the patient.

Twenty-six patients had ABT drains and 4 (15.4%) required an allogenic blood transfusion post-operatively. Sixteen patients received no drain and 5 (31.3%) required allogenic blood. There was no statistical difference between these two groups (p=0.22). There was no statistical difference (p=0.75) in the average day 1 haemoglobin drop between the ABT drain and no drain groups with haemoglobin drops of 2.80 and 2.91 respectively. There was no statistical difference in the length of hospital stay between the 2 groups (p=0.35). There was no statistical difference (p=0.26) in infection rates between the 2 groups (2 in ABT drains Vs. 0 in no drains). Of the 2 patients who experienced complications one had cellulitis and the other had an infected haematoma, which was subsequently washed out.

The results identify little benefit in using ABT drains to reduce the requirement for allogenic blood transfusion in the post-operative period following TKR. However, due to small patient numbers transfusion rates of 31.3% in the ABT drain group Vs. 15.4% in the no drain group cannot be ignored. Therefore further studies including larger patient numbers with power calculations are required before a true observation can be identified.

Introduction: Nowdays most of the health services focus on the reduction of expenses and the shorter hospital stay. For the patients is also important the faster rehabilitation in work and in full self-sufficiency.

Patients and methods: Möller has published in 1997, that medial unicompartmental knee arthroplasty can be operated from a shorter mediopatellar approach. This technique is important not only for the shorter wound, but much more for the faster rehabilitation because of the preserve of the extensor mechanism of the knee.

Between April 2000 and December 2002 we performed the minimal invasive medial unicompartmental knee arthroplasty in 36 cases. Our results were evaluated by the HSS knee score. The average follow up time was 24.7 months. We have compared our results to a similar group in age, number and follow up time, who has been operated in the traditional approach.

Results: However the overall HSS results showed significant difference (95.3 & 84.8), we think that the subgroups presents the substance of it much better. There was significant difference in walking distance, stair climbing, range of movement and muscle power, and we did not find any significant difference in pain, transport, flexion contracture, instability, need for appliance and the varus-valgus deformity.

Conclusion: In those cases, where both the patients win with the shorther rehabilitation and also the health service saves money with the reduction of expenses the minimal invasive way of operation should be more often used.

Aims: The purpose of this study was to determine whether patella replacement or RAP of the patella is advantageous in TKA.

Methods: 100 patients were recruited to enter a randomised, prospective, double blind clinical trial to determine the efþcacy of patellar resurfacing during total knee arthroplasty. All patients receive the same posterior cruciatesparing prosthesis, and all operations were performed by, or under the direct supervision of the þrst author. Evaluation consisted of the determination of the HSS-Score, the knee society scores, speciþc questions relating to patellafemoral symptoms, radiographs, measurement of torques and stability of one leg standing. All knees were followed at 3 month and 18 month postoperatively.

Results: There was no signiþcant difference between the two groups with regard to the HSS-Score, and the KS-scores. Excentric and concentric torques were higher in the group with RAP of the patella. One leg standing was more stable in the group with RAP of the patella. In both groups one patient complained of severe anterior knee pain. The patient with RAP of the patellar was treated successfully with secondary patella resurfacing.

Conclusions: The clinical outcome and the prevalence of anterior knee pain after TKA with the PFC-∑ knee was not inßuenced by whether or not the patella had been resurfaced. Force and balance are slightly better after TKA with RAP of the patella.

Introduction

In total knee arthroplalsties, there are risks of revision surgeries because of aseptic loosening, polyethylene wear, and metal component breakage. The data such as model, type, size, and manufacturing companies are required at the time of revision surgeries. However, it is sometimes difficult to acquire such data due to patient's change of address and the elimination and consolidation of hospitals in the long-term. Therefore, we try to use the Radio Frequency IDentification (RFID) in the total knee joint system.

Purpose

To compare Radiostereometric Analysis (RSA) and subjective outcomes of Total Knee Arthroplasty (TKA) and Total Ankle Arthroplasty (TAA).

Background

Total Knee Replacement (TKR) is technically demanding, time consuming and has higher complication rates in super obese (BMI>45) patients. Bariatric surgery can be considered for such patients prior to TKR although its effect on complications is unknown.

Orthopaedic surgeons and their patients continue to seek better functional outcomes after total knee replacement, but TKA designs claim characteristic kinematic performance that is rarely assessed in patients.

The objectives of this investigation is to determine the in vivo kinematics in knees with Cruciate Retaining TKA using Patient Specific Technology during activities of daily living and to compare the findings with previous studies of kinematics of other CR TKA designs.

Four knees were operated by Triathlon CR TKA using Patient Specific Technology and a fluoroscopic measurement technique has been used to provide detailed three-dimensional kinematic assessment of knee arthroplasty function during three motor tasks. 3D fluoroscopic analysis was performed at 4-month follow-up.

The range of flexion was 90°(range 5°–95°) during chair-rising, 80°(range 0°–80°) during step up and 100° (range 0°–100°) during leg extension. The corresponding average external rotation of the femur on the tibial base-plate was 7.6° (range +4.3°; +11.9°), 9.5° (+4.0°; 13.5°) and 11.6° (+4.5°; +16.1°). The mean antero-posterior translations between femoral and tibial components during the three motor tasks were +4.7 (−3.7; +1.0), +6.4 (−3.8; +2.6) and +8,4 (−4.9; +3.5) mm on the medial compartment, and −2.5 (−7.1; −9.6), −3.6 (−6.1; −9.7), −2.6 (−7.7; −10.3) mm on the lateral compartment, respectively, with the medial condyle moving progressively anterior with flexion, and the medial condyle moving progressively posterior with flexion.

We compared Triathlon CR PSI TKA results from this study with Genesis II CR TKA, with Duracon CR TKA, with Triathlon CR TKA and with the healthy knee kinematics. The results of this study showed no screw home mechanism. The internal rotation of the tibia with knee flexion is close to normal, better than Genesis II, Duracon and Triathlon CR TKA operated with standard surgery.

The medial condyle is characterized by the same pattern of the other implants, with a paradoxical anterior translation of 5 mm.

The lateral condyle shows a posterior rollback better than Triathlon CR operated with standard surgery.

For the first time is demonstrated that the surgical technique can modify the tibio-femoral kinematics.

Background and purpose: Development of minimal invasive operation techniques has given unicompartemental knee arthroplasty (UKA) renewed interest. Indications for use of UKA are however debated, and short-term advantages of UKA over total knee arthroplasty (TKA) should be weighed against the higher risk of reoperation. More knowledge on long term results of pain and function after knee arthroplasties is therefore needed and was the purpose of this study.

Methods: Patient-reported pain and function were collected at least two years after the operations in postal questionnaires from 1643 osteoarthritis patients reported to the Norwegian Arthroplasty Register with intact primary TKA (n=1271) or UKA (n=372). The questionnaire contained instruments for calculation of the knee specific Knee Osteoarthritis Outcome Score (KOOS), and for quality of life (EQ-5D, post- and pre-operative). 5 subscales from KOOS were used as outcome. To incorporate an outcome for anterior knee pain an additional subscale based on 7 questions from KOOS, clinically accepted to be related to such discomfort, was calculated. Pain and satisfaction from a visual analogue scale (VAS) were also used as outcomes together with improvement in EQ-5D index score. The outcomes were measured on a scale from 0 (worst) to 100 (best) units with an argued minimal perceptible clinical difference of 8–10 units. Group differences were analysed with multiple linear regression, adjusted for confounding by age, gender, Charnley category, time since operation and preoperative EQ-5D index score.

Results: UKA performed better than TKA for the KOOS subscales Activity in Daily Living (difference in mean outcome score =−3.4,p=0.02) and Sport and Recreation (difference =−4.4,p=0.02) and for Anterior Pain (difference=−4.5,p< 0.01). The difference was also significant for the outcome Pain(VAS) but now in favour of TKA (difference=3.3,p=0.02). Motivated by the discrepancy in the results of the pain related outcomes, Anterior Pain (UKA best), Pain(VAS) (TKA best) and Pain(KOOS) (no difference) further investigation of the questions (0=best to 4=worst) used for calculation of Pain(KOOS) and Anterior Pain were performed. Patients that had undergone UKA had more often pain from the knee (difference=0.26,p< 0.01), while they had less pain when they were bending the knee fully (difference=−0.37,p< 0.01) and less problems when squatting (difference=−0.25,p< 0.01).

Interpretation: Estimated differences did not reach the level of minimal perceptible clinical difference. There are however indication of differences in the way the two treatment groups experience knee related discomfort. Even though UKA offers a lower level of pain and less problems in activities involving bending of the knee, these patients seem to experience pain from the knee more often.

Background

Post operative analgesia is an important part of Total Knee Arthroplasty (TKA) to facilitate early mobilisation and patient satisfaction. We investigated the effect of periarticular infiltration of the joint with chirocaine local anaesthetic (LA) on the requirement of analgesic in the first 24 hrs period post op.

Many aspects of total knee arthroplasty have changed since its inception. Modern prosthetic design, better fixation techniques, improved polyethylene wear characteristics and rehabilitation, have all contributed to a large change in revision rates. Arthroplasty patients now expect longevity of their prostheses and demand functional improvement to match. This has led to a re-examination of the long-held belief that mechanical alignment is instrumental to a successful outcome and a focus on restoring healthy joint kinematics. A combination of kinematic restoration and uncemented, adaptable fixation may hold the key to future advances.

Cite this article: Bone Joint J 2015;97-B(10 Suppl A):16–19.

Background. Surgical wound closure is not the surgeon”s favorite part of the total knee arthroplasty (TKA) surgery however it has vital rule in the success of surgery. Knee arthoplasty wounds are known to be more prone to infection, breakdown or delayed healing compared to hip arthroplasty wounds, and this might be explained by the increased tensile force applied on the wound with knee movement. This effect is magnified by the enhanced recovery protocols which aim to obtain high early range of movement. Most of the literature concluded that there is no difference between different closure methods. Objectives. We conducted an independent study comparing the complication rate associated with using barbed suture (Quill-Ethicon), Vicryl Rapide (polyglactins910-Ethicon) and skin staples for wound closure following TKA. Study Design & Methods. Retrospective study where the study group included all the patients admitted to our unit for elective primary knee arthroplasty in 2015, we excluded patients admitted for partial knee arthroplasty, revision knee arthroplasty or arthroplasty for treatment of acute trauma due to the relatively higher complication rates. All the patients notes were reviewed to identify wound related problems such as wound dehiscence, wound infection and delayed healing (defined as delayed wound healing more than 6 weeks). Results. 327 patients were included in this study; 151 in Quill group, 99 in staples group and 77 in the last group where the wound closed with Rapide. We identified 9 (5.9%) cases of wound dehiscence in the Quill group, 3 cases of wound dehiscence in each of other two groups (3.8%) with Rapide and (3%) with staples. On the other hand superficial wound infection was higher with staples with 6 (6%) cases of wound infection compared to the other groups, wound infection occurred in 2 patients (2.5%) with Rapide and 5 patients (3.3%) in the Quill”s group. Most of the delayed wound healing happened after using Quill where it is reported in 5 patients (3.3%) and the lowest was in staples group with 1 patient (1%) and slightly higher percentage in Rapide group 2 patients (2.5%). The total figure of wound related problems was the highest in Quill”s group with 19 reported cases (12.5%), lower in staples” group with 10 cases (1.1%) and the lowest in Rapide”s group with 7 cases (9%). Conclusions. Our study showed different results to the reported literature suggesting that each closure method has its own advantages and disadvantages. Quill is quick, knotless and absorbable but on the other side it is significantly more expensive than other alternatives and it is associated with the highest complication rates. On the other hand Rapide is cheap absorbable alternative with the lowest percentage of wound problems but on the negative side it is time consuming. Finally staples method is the quickest, relatively cheap and rarely associated with wound dehiscence but it is not absorbable which might cause inconvenience to patients

Alignment and soft tissue balance are two of the most important factors that influence early and long term outcome of total knee arthroplasty. Current clinical practice involves the use of plain radiographs for preoperative planning and conventional instrumentation for intra operative alignment. The aim of this study is to assess the Signature. TM. Personalised system using patient specific guides developed from MRI. The Signature. TM. system is used with the Vanguard. R. Complete Knee System. This system is compared with conventional instrumentation and computer assisted navigation with the Vanguard system. Patients were randomised into 3 groups of 50 to either Conventional Instumented Knee, Computer Navigation Assisted Knee Arthroplasty or Signature Personalised Knee Arthoplasty. All patients had the Vanguard Total knee Arthroplasty Implanted. All patients underwent Long leg X-rays and CT Scans to measure Alignment at pre-op and 6 months post-op. All patients had clinical review and the Knee Society Score (KSS) at 1 year post surgery was used to measure the outcome. A complete dataset was obtained for 124 patients. There were significant differences in alignment on Long leg films ot of CT scan with perth protocol. Notably the Signature group had the smallest spread of outliers. In conclusion the Signature knee system compares well in comparison with traditional instrumentation and CAS Total Knee Arthroplasty

Purpose. Traditional total knee arthoplasty techniques have involved implantation of diaphyseal stems to aid in fixation expecially when using constrained polyethylene inserts. While the debate over cemented vs uncemented stems continues, the actual use of stems is considered routine. The authors' experience with cemented stemmed knee revisions in older patients with osteoporotic bone has been favorable. Our younger patients with press-fit stems from varying manufacturers have been plagued with a relatively high incidence of component loosening and stem tip pain in the tibia and occasionally thigh. We report the early results of the first 20 total knee revisions using press-fit metaphyseal filling sleeved stemless implants with constrained bearings. Methods. Twenty three patients with failed primary or revision total knees were assigned to receive stemless sleeved revision knee designs using the DePuy MBT/TC3 system. Reasons for revision included loosening, implant fracture, stiffness, instability, and stem pain. Twenty patients (ages ranging from 42–73) were successfully reconstructed without stems. Six knees with significant uncontained cavitary defects were included. Three patients with unexpectedly osteoporotic metaphyseal bone were revised with cemented stemmed implants and excluded. All cases used cement for initial fixation on the cut bone surface and fully constrained mobile bearing inserts. Results. Follow up ranged from six months to three years. All patients had radiographic evidence of well fixed stable implants on most recent examination. All four cases of revision for “end of stem pain” had complete resolution of symptoms within two weeks of revision surgery. Long leg anterior posterior mechanical alignment x-rays measured within two degrees of neutral in all cases. Knee Society Scores improved an average of 34 points. Clinical results for revision for stiffness had the lowest final scores post operatively. Conclusion. Stemmed total knee arthroplasty revision implants with or without cement are considered the standard for most revision reconstructions. Recently, primary total hip replacements using newer short metaphyseal stems have shown promising early clinical results. This case series of twenty total knee revisions using stemless press-fit metaphyseal sleeves shows similarly favorable outcomes. The complications of stemmed implants such as stem tip pain and difficulty of cemented stem removal can be avoided successfully in non-osteporotic bone reconstructions. With stable bony ingrowth visible on early post-operatyive radiographs, long term stable fixation even with constrained bearings is expected. Longer follow up will be needed to validate this technique for routine use

Background. Cement restrictors are used for maintaining good filling and pressurization of bone cement during hip and knee arthroplasties. The limitations of certain cement restrictors include the inability to accommodate for large medullary canals particularly in revision procedures. We describe a technique using SurgicelTM (Johnson & Johnson) and SPONGOSTAN™ (Johnson & Johnson) (Fig 1) to form a cement restrictor that can accommodate for large canal diameters and provide excellent pressurisation. Technique. The technique involves the application of SPONGOSTAN™ (Johnson & Johnson) foam onto a SurgicelTM (Johnson & Johnson) mesh which is then rolled onto the SPONGOSTAN™ foam forming a uniform cylindrical structure Figs 2,3. The diameter of the restrictor can be adjusted according to the desired femoral canal diameter through increasing the thickness of the SPONGOSTAN™ (Johnson & Johnson) foam. The restrictor is then inserted into the desired position in the medullary canal where it expands uniformly creating an effective restrictor and bone plug Fig 4. Bone cement is then applied and pressurisation commenced prior to the insertion of the implant Fig5. SPONGOSTAN™ is an absorbable haemostatic sponge intended for haemostatic use by applying to a bleeding surface. It consists of a sterile, water-insoluble, malleable, porcine gelatin absorbable sponge. Surgicel ™ is an absorbable hemostatic agent composed of oxidized regenerated cellulose. It is a sterile, absorbable knitted fabric that is flexible and adheres readily to bleeding surfaces. Both products are routinely used for their haemostatic properties in various surgical disciplines. Discussion. The use of intramedullary plugs in cemented total joint arthroplasty is essential in order to achieve good filling and pressurization in hip and knee arthoplasties, traditionally, a small piece of bone or a cement restrictor may be used to plug the shaft. Distal plugs seal the femoral canal, improve fixation and prevent bone cement from leaking during delivery and pressurization. Plugging the intramedullary canal during total hip arthroplasty increases penetration of cement into cancellous bone proximal to the intramedullary plug. Numerous plug designs and materials are available ranging from non-resorbable to resorbable. Regardless of design, all restrictors should avoid intramedullary cement leakage and plug migration during cement and stem insertion to ensure adequate intramedullary pressures. In some instances the diameter of the femoral canal is too wide to accommodate a conventional cement restrictor particularly when crossing the femoral isthmus and even more so in revision procedures requiring the implantation of long stemmed cemented components. The use of the Surgicel-Spongostan haemostatic restrictor overcomes some of the limitations of a standard cement restrictors. These include the ability to bypass a narrow femoral isthmus, accommodate large femoral canals, particularly in revision procedures, and the flexibility of adjusting the restrictor to the desired diameter of the medullary canal and in effect providing a bespoke cement restrictor. This technique was used successfully in over 300 revision hip and knee procedures with no adverse effects and excellent outcomes

Total knee arthoplasty (TKA) remains a standard treatment for advanced knee arthritis. The aim of the procedure is to restore function and relieve pain ideally for the rest of patient's life. Patient matched templating (PMT) or patient specific instrumentation (PSI) is a recent development for alignment of TKA components that uses disposable guides. The users of PSI claim it to be the optimum balance of new technology and conventional technique by reducing the complexity of conventional alignment and sizing tools. To assess the clinical and radiological outcome of Primary TKA done with PSI. More than 200 cases of TKA have been done in our unit using PSI and we analysed the radiographic outcome of these cases postoperatively. We also reviewed the clinical outcome of 103 patients with 1 year and 43 patients with 2 year follow-up. Data was collected prospectively: pre-operatively and at 1 year and 2 years post-operatively including Oxford knee score (OKS), WOMAC and American knee society score (AKS). Standard AP and lateral films were done pre-operatively and post-operatively. Mean age was 66 years. There were 56 female and 47 male patients. Mean post-operative angles on standard films were: Alpha = 95.6, Beta = 88.4, Saggittal femur = 3.4 and Saggittal tibia = 90.8. Of the 103 cases with 1 year follow-up, there was significant improvement in all clinical outcome scores. Mean OKS improved from 18 to 39 at 1 year and remained the same at 2 years, WOMAC improved from 40 to 18 in both 1 and 2 years post-op. AKS Total improved from 79 to 173 at 1 year and 170 at 2 years. Performing TKA using PSI is safe and provides good radiological alignment in the coronal and sagittal plane. Significant improvement in outcome scores were seen at one and two year follow up and reached levels that compared favourably with other reported series of TKA outcome from our unit

To evaluate prospectively the mid-term results of the Zimmer Unicondylar Knee arthoplasty (UKA). Between 2005 and 2012, 187 unicompartmental knee arthroplasties (UKA) were performed by a single surgeon using a fixed-bearing prosthesis (Zimmer). 37 cases were excluded as either were lost to follow-up or had less than six months follow-up. The study included 150 UKAs. Deformity, if present, was correctable. Patellofemoral joint (PFJ) disease was not considered as an absolute contraindication. The average patient age at the time of surgery was 66 years (range 42–88 years); 78 of which were male. Mean follow-up time was 3.6 years (range 7–81 months). Mean Body Mass Index (BMI) was 29 (range 21–41). Clinical and conventional radiological evaluations were carried out at six months, one, two and five years postoperatively. 147 cases were medial compartment replacement and three were lateral. 86 patients had grade III OA and 64 had grade IV (Kellgren and Lawrence). 113 patients had an element of PFJ disease. The mean Knee Society knee and function scores had an improvement from 55 and 54 points pre-operatively to 95 and 94 points respectively at time of most recent evaluation. The average flexion improved from 116 degrees pre-operatively to 127 degrees. Two cases were revised, one due to progression of osteoarthritis in the lateral compartment of the knee and the other was due to arthrofibrosis. The Zimmer unicompartmental knee arthroplasty provided excellent pain relief and restoration of function in carefully selected patients. However, long-term studies are necessary to investigate the survival rate for this prothesis

Aim. We aim to compare revision rates and functional outcome scores in between two contemporary total knee arthoplasty systems. Methods. A search was carried out of a prospectively maintained outcomes database to identify all patients receiving total knee replacement (TKR) in the department between 2005 and 2006, when evaluation of different knee arthroplasty systems was being undertaken. Data on the first 93 consecutive patients receiving a Scorpio (Stryker, Allendale, NJ) implant and the first 93 consecutively receiving a PFC (DePuy, Warsaw, IN) implant were reviewed. Four year revision rates and functional scores were recorded. Results. Patient demographics were similar in both groups. Six of ninety three Scorpio implants were listed for revision over the four year period (6%). Five of these were for aseptic loosening. Three further patients are currently being investigated for pain and have radiological evidence of loosening with no clinical evidence of infection. No PFC implants required revision in the four year period (p = 0.013). There was no difference in Oxford Scores pre-operatively, or at 3 months, 1 year and 2 years post-operatively. Discussion. There is a significant difference in revision rates between the two prostheses, and the revision rate of the Scorpio prosthesis is far higher than would be expected. The majority of these have been revised for aseptic loosening. Those prostheses surviving to four years had similar clinical outcomes. The reasons for this higher than expected revision rate in the Scorpio group require further exploration

Aims

The aim of this study was to evaluate medium- to long-term outcomes and complications of the Stanmore Modular Individualised Lower Extremity System (SMILES) rotating hinge implant in revision total knee arthroplasty (rTKA) at a tertiary unit. It is hypothesized that this fully cemented construct leads to satisfactory clinical outcomes.

Ligament balancing can be difficult to perfect in total knee arthoplasty (TKA), where current surgical practice is subjective and highly dependent on the individual surgeon. Proper ligament balancing contributes to postoperative stability, prosthetic alignment, and proprioception. Conversely, imbalance is linked to increased wear rates of the polyethylene component within the implant and, in turn, early surgical revision. With the end goal of quantification of joint compartmental pressures, pressure sensor arrays have been designed to quantify contact stresses within the knee during TKA. Flexible, capacitive pressure sensors are designed as simple parallel plates, enabling a robust solid state design. Modification of cleanroom microfabrication processes enable realization of these arrays on polyimide (common in microdevices), and polyethylene (common in joint replacements). Readout circuitry implements an Analog Devices capacitance to digital chip and output is compared to direct LCR meter data. Testing verifies the highly linear response of the sensors with applied normal loads corresponding to pressure magnitudes present in passive (intraoperative) knee flexion. Spatial resolution of the arrays is 0.5 mm, with a critical dimension of 25 micrometers, allowing the magnitude and location of forces to be accurately recorded. The MEMS pressure sensors are mounted on a tibial trial, with the body of the trial housing all circuitry. The sensors are read sequentially, and the data undergoes analog to digital conversion prior to wireless data transmission at 2.4 GHz. An Instron machine is used for compressive loading for laboratory calibration and testing. This paper outlines device fabrication, readout circuit implementation, and preliminary results

Orthopedic surgery is one of the most blood-consuming surgeries. Currently there has been a radical change in transfusion policies, developing a series of therapeutic measures essentially created to minimize the use of allogeneic blood. On the one hand, the safety of our patients must be even more our main objective. On the other hand, our economic resources are more restricted and therefore we must evaluate our surgical techniques and proceedings in order to be safer and more cost-effective. The aim of this study is to report our results of the blood lost, the percentage of blood loss, the necessity of transfussions and how many blood pakages are needed. From a sample of 2400 total knee arthroplasties proceedings, we analyze some surgical proceedings such as lligament balance, patelar traking, artrotomy, ischemia, femoro-tibial axis and type of arthroplasty. We also examine the total blood lost and the percentage of total blood loss after 4 hours, after 24hours and after 48 hour of the total knee arthoplasty surgery. We made a statistical analysis with t-test or anova test when it was necesassary. The outcome of our investigation show that the blood loss when the ischemia is less than 50 minutes is 1470 cc and 1603 cc when is more than 50 minuntes (p<0.05). If we use the medial arthrotomy, the total bleeding is 1563cc, but with subvastus arthrotomy is 1294cc (p<0.05). If we use a primary rotational total knee arthroplasty the bleeding is 953cc, but if we use a PS or PCR the bleeding is 874cc (p<0.05). As a conclusion we should know that our patients have more blood loss when the ischemia is more than fifty minutes, the bleeding is higher when we make a medial arthrotomy and when we use a rotational knee primary arthroplasty

Purpose. The patella provides a mechanical advantage to the knee extensor mechanism. Patellectomy, performed for trauma or patellofemoral arthrosis, does not preclude the development of tibiofemoral arthrosis. Total knee arthroplasty is the mainstay of treatment for tibiofemoral arthrosis. The purpose of this study was to evaluate the outcomes of total knee arthoplasty in patients who previously underwent patellectomy. Method. A retrospective analysis was completed on a prospectively collected database to identify all patients who underwent total knee arthroplasty following a previous patellectomy. Sixty-one total knee arthroplasties in 57 patients were identified. Patient demographics as well as functional outcome scores, including WOMAC and Knee Society Scores, were evaluated. Results. Thirty-six females (63.2%) and 21 males (36.8%) underwent a Total knee arthroplasty between July 1984 and April 2010. Mean follow up was 6.0 years (3 months–20 years). Mean Age and BMI was 59.8 8.6 and 30.5 5.8 respectively. Patellectomy was performed for trauma (56) and patellofemoral arthosis (five). All polyethylene inserts were cruciate substituting. There were five deaths and 10 knees (16.4%) required revision surgery. Causes for failure included aseptic loosening (2), polyethylene wear (3), component fracture (2), infection (2) and stiffness (1). WOMAC scores improved from 38.0 14.1 pre-operatively to 58.5 22.1 at latest review. Knee Society scores improved from 81.5 31.2 to 136.0 41.0. Range of motion and extensor lag changed preoperatively from 105.7 15.9 and 4.3 15.5 degrees to 110.7 12.1 and 6.3 7.1 degrees postoperatively. Conclusion. Despite the mechanical disadvantage to the knee extensor mechanism rendered by patellectomy, total knee arthroplasty is an effective treatment option for tibiofemoral arthrosis in these patients

Aim: To identify the microbiology of infected knee arthroplasty, emerging patterns of resistance over the last decade, and suggest appropriate empirical treatment. Methods: A retrospective analysis was conducted of 121 patients with microbiologically proven infection, who underwent revision TKA between 1994–2008. The causative organism was identified from microbiological samples and the corresponding sensitivities recorded. The data was then collated to determine the most common causative organisms, changing patterns of antibiotic resistance over the time frame, and the antibiotics currently most effective at treating deep infection. A theoretical model combining gentamicin with other antibiotics was used to determine the most effective antibiotics for use as empirical treatments. Results: Coagulase negative Staphylococcus (CNS) was the most common causative organism (49%). Staphylococcus aureus (SA) accounted for 13% of cases. The prevalence of CNS appears to be increasing, while that of SA and other organisms is decreasing. Vancomycin and teicoplanin were the most effective antibiotics with overall sensitivity rates of 100% and 96% respectively. Levels of resistance were significantly higher among the antibiotics commonly used in the community. Antimicrobial resistance was higher when the causative organism was CNS, suggesting that MRSE is becoming a problem in knee arthroplasty. Our theoretical model showed that gentamicin combined with vancomycin would be the most effective empirical treatment. Conclusion: Understanding the microbiology of deep infection of the knee allows surgeons to treat this complication as effectively as possible. Vancomycin and tei-coplanin appear to be the most effective antimicrobials, with relative invulnerability to the development of resistance. Given the effectiveness of these antibiotics, the use of vancomycin in gentamicin bone cement, combined with IV teicoplanin potentially allows for infected knee arthoplasties to be treated with a one-stage procedure. The rational use of antibiotics may help limit the amount of antibiotic resistance which develops in the future

Inflammatory changes in synovial tissues occur commonly in knee osteoarthritis (OA) and are termed “inflammatory OA”. The pathogenic significance of this inflammatory OA is uncertain. It is also not known whether inflammatory changes in the synovial membrane are reflected in the synovial fluid (SF) and whether the SF contains a similar inflammatory cell infiltrate. This study examined 34 cases of knee joint OA and cytologically and immunohistochemically characterised inflammatory cells in the synovial membrane and SF. Specimens of SF and synovial membrane were taken at the time of knee arthroplasty. All cases of inflammatory OA synovium contained (CD68+) macrophages; several cases also contained a scattered, focally heavy (CD3+) lymphocytic infiltrate and occasional lymphoid aggregates. Inflammatory changes in OA SF reflected this cell composition with numerous CD68+ macrophages and CD3+ lymphocytes being noted in inflammatory OA cases. The SF volume was greater (> 5ml) in cases of inflammatory OA. Non-inflammatory OA knee joints contained very few inflammatory cells, which were mainly macrophages, in both the synovial membrane and SF. Our findings indicate that inflammatory changes in the synovial membrane of OA knee joints are reflected in the SF and that the volume of SF is commonly increased in cases of inflammatory OA. Both macrophages and lymphocytes in the inflammatory infiltrate of knee joint SF may contribute to joint destruction in OA by providing mononuclear phagocyte osteoclast precursors and the production of inflammatory cytokines and growth factors that promote osteoclastogenesis. In conclusion, the cytology of SF and synovitic membrane are similar in inflammatory OA. With knee effusions of greater than 5mls and inflammatory synovitic membrane consideration of total knee arthoplasty in the presence of single compartment disease should be considered because of the risk of further joint destruction

Aim: The purpose of the study is to determine the opioid Ð sparing effect of Rofecoxibe and Lornoxicam in comparison to placebo in total knee arthoplasty. Method: This was a prospective, randomized, double-blind study. 82 patients with mean age of 70 years old (±3.5) and weight 82 (±4) were included. The operation was done under spinal anaesthesia. All patients after the operation were transferred to the Orthopaedic High Dependency unit where PCA morphine with a bolus of 1 mgr and lock-out interval of 8 min was started. There were randomized to receive 50 mgr of Rofecoxibe orally the morning of the operation or 8 mg of Lornoxicam I.V. twice a day. The third group did not receive any additional analgesic. After 24 hours the consumption of morphine and the evaluation of pain according to VAS scale were recorded. The evaluation of pain was done by the same doctor. Results: There was no statistically signiþcant differences between the three groups either in the consumption of morphine or the pain intensity (Wilcoxon test)Conclusions: Our study showed that the administration of Rofecoxibe 50 mg per os, Lornoxicam 8 mg I.V/b.d. or placebo makes no difference either in the consumption of morphine or the pain intensity during the þrst 24 hours

Purpose: To review long-term outcome following knee arthrodesis, and compare this with patient outcome following revision knee arthroplasty. Methods: Case notes and radiographs of patients who underwent arthrodesis using the Mayday nail were reviewed retrospectively for evidence of clinical and radiological union. Patients also completed an SF12 health survey and Oxford knee score in the form of postal questionnaires. Each patient was matched with patients who had undergone revision knee arthoplasty and the outcomes were compared. Results: 19 patients were reviewed who underwent knee arthrodesis using a Mayday nail in two centres between 1993 and 2004. 18 cases had united clinically and radiologically with one case lost to follow-up. Mean SF12 scores of patients following knee arthrodesis indicated severe physical (28.8) but only mild mental (43.3) disabilities. The mean Oxford knee score in this group was 41.0. These results were comparable with matched patients following revision knee arthroplasty who scores 27.2 (physical) and 41.1 (mental) on the SF12, and a mean of 38.8 on the Oxford knee score. Conclusion: Outcome scores following knee arthrodesis were similar to those following revision knee arthroplasty making it an option worth considering in selected patients requiring revision surgery. Discussion: The Mayday nail provides a method of knee arthrodesis with a high union rate and an acceptable complication rate. Outcome scores following arthrod-esis were not dissimilar to those following revision total knee replacement. These results suggest that knee arthrodesis may be considered as an acceptable alternative to complex knee revision surgery

Aim: To identify the microbiology of infected knee arthroplasty, emerging patterns of resistance over the last decade, and suggest appropriate empirical treatment. Methods: A retrospective analysis was conducted of 121 patients with microbiologically proven infection, who underwent revision TKA between 1994–2008. The causative organism was identified from microbiological samples and the corresponding sensitivities recorded. The data was then collated to determine the most common causative organisms, changing patterns of antibiotic resistance over the time frame, and the antibiotics currently most effective at treating deep infection. A theoretical model combining gentamicin with other antibiotics was used to determine the most effective antibiotics for use as empirical treatments. Results: Coagulase negative Staphylococcus (CNS) was the most common causative organism (49%). Staphylococcus aureus (SA) accounted for 13% of cases. The prevalence of CNS appears to be increasing, while that of SA and other organisms is decreasing. Vancomycin and teicoplanin were the most effective antibiotics with overall sensitivity rates of 100% and 96% respectively. Levels of resistance were significantly higher among the antibiotics more commonly used in the community. Antimicrobial resistance was higher when the causative organism was CNS, suggesting that multi-drug resistant CNS is becoming a problem in knee arthroplasty. Our theoretical model showed that gentamicin combined with vancomycin would be the most effective empirical treatment. Conclusion: Understanding the microbiology of deep infection of the knee allows surgeons to treat this complication as effectively as possible. Vancomycin and teicoplanin appear to be the most effective antimicrobials, with relative invulnerability to the development of resistance. Given the effectiveness of these antibiotics, the use of vancomycin in gentamicin bone cement, combined with IV teicoplanin potentially allows for infected knee arthoplasties to be treated with a one-stage procedure. The rational use of antibiotics may help limit the amount of antibiotic resistance which develops in the future

Aims: Should the tibial tray be rotated about the femoral component of a total knee arthroplasty? Literature review provides evidence commending rotation and neutral alignment. We wanted to provide evidence to help this debate. Method: We developed a knee jig allowing full range of movement of a knee arthoplasty. Under compression, we studied the isolated effect of tibial tray rotation about the femoral prosthesis in þxed and mobile bearing prostheses. We photographed the tibio-femoral and patello-femoral articulations. Results: A mobile bearing prosthesis at 15 degrees of tray rotation suffered posteromedial and anterolateral polyethylene impingement. At 25 degrees, the medial femoral component lifted off. The þxed bearing prosthesis showed similar polyethylene impingement, but no femoral condyle lift off. In both prostheses, tray rotation increased lateral patella facet loading, which increased with knee ßexion. Conclusion: Mobile bearing prosthesis was less tolerant than þxed bearing prosthesis to tibial tray rotation. Rotation caused polyethylene impingement, which would generate wear debris. Patella tracking was not improved by tibial tray rotation. The mobile bearing prosthesis is less congruent at the tibio-femoral articulation. Therefore there is less Òdriving forceÒ to rotate the polyethylene to align it to the femoral component, when the tray is rotated. We recommend the tibial tray be aligned to the femoral prosthesis in neutral

Introduction. Patellofemoral complications remain a very common post-operative problem in association with total knee arthoplasty (TKA). As malrotation of the femoral component is often considered crucial for the outcome, we analyzed absolute rotational femoral alignment in relation to patellar tracking pre- and postoperatively and matched the results with the two year functional outcome. Methods. Femoral rotation and component rotation was assessed by axial radiography using condylar twist angle (CTA). The lateral patellar displacement, patellar tilt and Insall-Salvati index were measured on conventional radiographs. All assessments were done pre-operatively and at 2-year follow up. The series included 48 consecutive TKA (21 men, 27 women) performed at a single high-volume joint-replacement-center in 2008. All operations were performed using a tibia first-ligament balancing technique without patella resurfacing. The implant used was a condylar unconstrained ultracongruent rotating platform design. Outcome was assessed using the international knee society score (KSS) and the Kujala Score for anterior knee pain. Results. Preoperative CTA showed 6.4±2. 5° (X±SD) of internal femoral rotation (IR) (range, 1° of external rotation (ER) to 12° of IR) compared to postoperative CTA of 3.9°±2.98° (X±SD) of IR (range, 9.5° IR to 3.8°of ER) Preoperative patella lateral displacement showed a mean of 1.1mm (−2mm, 6mm), compared to postoperative patella lateral displacement with a mean of 1.7mm (−3mm, 6mm). Postoperative mean patella tilt was 6.65° (1.8°, 11.7°) postoperatively compared to 8.55° (4.3°,11.5°) preoperatively. No correlation was found between CTA post surgery and patella positioning (r=0.034, 95% CI). IR of the femoral component >3°did not show increased patella lateral displacement/tilt compared to 0° or ER. No correlation was found between the Kujala score and internal rotation of the component (r=0.082, p=0.05). At 2 year post OP KSS reached > 185 of max. 200 points in over 82% of patients. Conclusion. The influence of IR of the femoral component on patellofemoral kinematics remains controversial. As demonstrated, IR does not imperatively lead to patella maltracking and/or patellofemoral symptoms. Functional outcome in this series shows that relative rotation of the femoral component in accordance with natural variations as seen in the pre-operative assessment allows for good and excellent results

Introduction. A few follow-up studies of high flexion total knee arthoplasties report disturbingly high incidences of femoral loosening. Finite element analysis showed a high risk for early loosening at the cement-implant interface at the anterior flange. However, femoral implant fixation is depending on two interfaces: cement-implant interface and the cement-bone interface. Due to the geometry of the distal femur, a part of the cement-bone interface consists of cement-cortical bone interface. The strength of the cement-bone interface is lower than the strength of the cement-implant interface. The research questions addressed in this study were: 1) which interface is more prone to loosening and 2) what is the effect of different surgical preparation techniques on the risk for early loosening. Materials & methods. To achieve data for the cement-(cortical)bone interface strength and the effects of different preparation techniques on interfacial strength, human cadaver interface stress tests were performed for different preparation techniques of the bony surface and the results were implemented in a finite element (FE) model as described before. The FE model consisted of a proximal tibia and fibula, TKA components, a quadriceps and patella tendon and a non-resurfaced patella. For use in this study, the distal femur was integrated in the FE model including cohesive interface elements and a 1 mm bone cement layer. In the model, the cement-bone interface was divided into two areas, representing cortical and cancellous bone. The posterior-stabilised PFC Sigma RP-F (DePuy, J&J, USA) was incorporated in the FE knee model following the surgical procedure provided by the manufacturer. A full weight-bearing squatting cycle was simulated (ROM = 50°-155°). The interface failure index was calculated. Results. Overall, the highest stresses were found at the proximo-medial part beneath the anterior flange of the femoral component. Highest shear stresses were found at the cement-implant interface (peak shear stress of 3.33 MPa at 150° of flexion). Highest tensile stresses were found at the cement-cortical bone interface (peak tensile stress of 1.30 MPa at 150° of flexion). The failure index was highest at the cement-bone interface. When the total anterior flange was covering cancellous bone, 0.4% of the cement-bone interface would fail and 0% of the cement-implant interface at 145° of flexion. In the more realistic simulation of cortical bone with periost, almost 31.3% of the complete cement-bone interface would fail even within normal range of motion (<120°). This can be reduced by drilling holes through the cortex to 2.6%. Discussion. Obviously, the FE knee model utilized in this study contains limitations which may have affected the interface stresses calculated. However, the results presented here clearly demonstrate high risk of early loosening at the cement-bone interface. This risk can be reduced by some simple preparation techniques of the cortex behind the anterior flange. Proper anterior fixation of the femoral component, and thus adequate surgical technique, is essential to reduce the risk of femoral loosening for high-flexion TKA

Purpose. Prospective randomized intervention trial to determine whether patients undergoing rotating platform total knee arthroplasty have better clinical outcomes at two years when compared to patients receiving fixed bearing total knee arthroplasty as measured by the WOMAC, SF-36 and Knee Society (KSS) scores. Method. 67 consecutive patients (33 males and 34 females; average age 66 years) were randomized into either receiving a DePuy Sigma rotating platform (RP) total knee arthroplasty (29 patients) or a DePuy Sigma fixed bearing (FB) total knee arthroplasty (38 patients). Inclusion criteria included patients between the ages of 45–75 undergoing single-sided total knee arthoplasty for clinically significant osteoarthritic degeneration. Pain, disability and well-being were assessed using the WOMAC, KSS, and SF-36 preoperatively and at 6 months, 1 year and 2 years post-operatively. In addition, intraoperative measures were collected. Pre-operative radiographs were analyzed using the Kellgren and Lawrence Score, modified Scotts Scoring and mechanical axis. Post-operative radiographs were collected at 1 and 2 years and analyzed to identify evidence of prosthetic loosening, implant positioning and limb alignment. Results. The two groups were well-matched following randomization (age, BMI, side) and had no significant differences in intraoperative measures (operative time, estimated blood loss). There were no differences in the groups with respect to their preoperative radiographs. The average female patient was younger compared to their male cohorts (mean female = 63; mean male 68 p=0.005). The post-operative radiographs did not reveal any differences between RP and FB groups when comparing sagittal alignment of femoral and tibial components, patellar tilt and patellar location. With respect to clinical outcomes, both groups reported statistically significant improvements in KSS, WOMAC and SF-36 scores. There were no differences in their pre- and post-operative SF-36 mental component scores. The 1 year WOMAC function score was significantly higher (worse outcome) in the FB group (mean = 18) compared to the RP group (mean 7.8) (p < 0.01). Two year KSS scores were significantly higher (better outcome) in the FB group (mean = 95.7) compared to the RP group (mean = 85.9) (p < 0.05). Conclusion. Both rotating platform and fixed bearing total knee arthroplasty result in clinical improvement over pre-operative function, but has no effect on the mental component of the SF-36. The current study suggests that there is not a clear benefit in selecting either a rotating platform or a fixed bearing total knee system; rather both implants result in improved function. Interestingly, when comparing the results of the WOMAC and KSS, although both measure functional outcomes, when applied to the same population demonstrate differing sensitivity

One hundred and ninety patients requiring total knee arthroplasty were randomized to one of two treatments: retaining or sacrificing the posterior cruciate ligament during surgery. Both groups received a Genesis II implant (Smith and Nephew Richards) appropriate to the treatment. Patients were seen preoperatively, at three months, one year, and two years. The end-of-study date is at five years postoperatively. Outcome measures include range of motion, the KSCRS, SF-12, and WOMAC. At two years both groups have shown improvement in pain, function, and stiffness. There is no apparent difference between groups with regard to any outcome measures or complications. The purpose of this study was to compare retaining vs. sacrificing the posterior cruciate ligament (PCL) in total knee arthroplasty in the patients who satisfy the criteria for a cruciate retaining knee. Two years after total knee replacement, both groups have improved knee function, less pain, and less knee stiffness. There is no apparent difference between the groups with regards to range of motion, function, or other outcome measures. Designs of total knee arthoplasty implants, as well as surgical techniques continue to evolve. The role of the PCL in primary total knee arthroplasty remains controversial. Current prosthetic designs have the flexibility to either substitute for a resected PCL or allow preservation of the ligament. One hundred and ninety patients requiring total knee arthroplasty upon satisfying the criteria for a cruciate retaing arthroplasty were randomized to receive either a posterior cruciate retaining implant or a posterior cruciate sacrificing implant. Surgery was performed following standard procedure with the only difference between groups being the sacrificing or retaining of the PCL. Patients were followed at three months, one year, and two years postoperatively. Outcome measures included range of motion, the Knee Society Clinical Rating Score (KSCRS), SF-12, and Western Ontario and McMaster Osteoarthritis Index (WOMAC). Early results indicate that both groups are doing equally well with no statistical difference in outcomes at two years. There is a trend toward increased range of motion at six and twelve months in the PCL sacrificing group. A six- degree gain was noted in the sacrificed group as compared to a two degree gain in the intact group. Funding: Smith and Nephew

Purpose: We expose technical problems encountered for prosthesis replacement in osteoarthrosis juvenilis (OJ). The characteristic feature of this disease is early joint destruction during growth. Material and methods: Total knee arthoplasty (TKA) was performed in 17 severely disabled patients (31 knees): Steinbrocker stage II=30%, stage III=30%, stage IV=40%. Mean age at operation was twenty years (14–29). Technical difficulties were related to the following combinations: 1) multidirectional malformations, generally in valgus (mean 16°, range 5–30°) in 30% of the knees associated with external rotation (mean 20°, range 5–50) and sagittal deformation with permanent flexion (mean 31°, range 5–60°) with external or posterior tibia dislocation; 2) limited joint motion: 71° (0–115°); 3) extraarticular deformations with permanent flexion or vicious hip rotation, tibial or femoral callus; 4) major condyle dysplasia due to growth deficiency (3/31 or necrosis (3/31); 5) low patella (100%) and subluxation; 6) weak bone and fragile skin related to corticosteroid therapy; 7) persistent growth cartilage in four patients. We tried to implant the most adapted prosthesis in each individual situation, favouring the least constrained implant possible. Results: We used fifteen mobile plateau prostheses including five pure gliding TKA and ten posterostabilised TKA with a mobile plateau and 16 hinge prostheses with two rotators. Thirty of the 31 TKA were custom-made. Discussion: Our different approaches enabled us to propose the following: correction of extra-articular deformations by TKA, after tenotomy and traction, or after concomitant osteotomy; primary approach after checking the vasculonervous bundle (popliteal sciatic); sub-periosteal dissection preserving the lateral ligaments searching to achieve ligament balance when possible in order to implant the least constrained implant possible; non-cemented implants, especially for “soft” or “fatty” bone; no patellar resurfacing when there is a risk of an overly thick low and subluxed patella

Spontaneous osteonecrosis of the knee (SPONK) usually involves a single condyle or plateau. The medial femoral condyle is most often involved and spontaneous osteonecrosis of medial tibial plateau is a rare condition, representing only 2 % of all necrosis reported in the knee. Therefore, SPONK with both involvement of medial femoral condyle(MFC) and medial tibial plateau(MTP) might be extremely rare. SPONK in each MFC or MTP respectively might be extended into corresponding side of the knee at their advanced final stage, howevere, in that situations, significant degenerative change would accompany and it might be difficult to differentiate final staged SPONK form severe osteoarthritis. To the best of our knowledge, SPONK affecting both medial femoral condyle and medial tibial plateau without significant secondary osteoarthritis changes is not reported, even though it was difficult to know which occurred first. We experienced 3 patients with histologically proven osteonecrosis of the medial tibial condyle and medial tibial plateau, and report their radiologic features. All 3 patients showed similar ridiograhic patterns. Medial portion of medial tibial plateau and lateral portion of medial femoral condyle showed longitudinal fracture like-subchondral collapse. Standing anteroposterior radiograph at 30 degree knee flexion showed well fitted features such as “locked” medial condyle. Varus angulation was present. Significant degenerative changes was not shown except for subchondral sclerosis. T1-weighted coronal and Fat suppressed T2-weighted MR images showed subchondral collapse with ill-defined diffuse bone marrow edema changes on both tibial and femoral condyles. At surgical findings, longitudinal track-like groove was shown in both medial femoral condyle and medial tibial plateau. Articular cartilage was denuded and showed glistening surface with bone defect of lateral side of medial femoral condyle and medial side of tibial articular surface. Histological analysis shows necrotic bone, surrounded by an area of fibrovascular granulation tissue on both femoral and tibial sides. Total knee arthoplasty was performed in all 3 patients. As a result of very low prevalence of both involvement of MFC and MTP and limited number of our cases, we could not conclude that radiologic features in our cases are typical radiologic pattern of both involvement. However, based on our cases, we believe that this characteristic radiologic features may considered as one of the possible various radiologic findings of simultaneous involvement in MFC and MTP and allow diagnosis for SPONK with both involvement in MFC and MTP to be facilitated

Purpose: The results of infected total knee arthroplasty management are studied, in order to evaluate the effectiveness of our treatment protocol, which is based on clinical manifestations of the infection. Material: 22 infected total knee arthoplasty were studied (9 of them had been send from other hospitals). Method: According to the clinical manifestations of the infection, patients were treated with one of the following methods: In the first group, 7 patients with primary postoperative infection (within the first 3 weeks after the operation) and with no MRSA pathogen, were treated with surgical debridement, keeping off the wound drainage for a long period and with antibiotic administration for 6–12 weeks. In the second group, 10 patients with late onset of infection or primary infection with MRSA pathogen or acute hematogenic infection with loose implant, were treated with wide surgical debridment, removal of all the materials and revision surgery after a 2–3 months period of antibiotic administration. In the third group, 3 patients with acute hematogenic infection but stable implants 2 to 6 years postoperatively, were treated with meticulous surgical debridement, exchange of polyethylene and administration of antibiotics for a long period. In the fourth group, 2 very old patients with bad general condition, were treated only with antibiotics. Results: In the first group there is full eradication of the infection and there is no indication of recurrence (F.U 2–6 years). In the second group 8 patients had their infection fully eradicated and 2 patients recurrended 6 and 8 months postoperatively. One underwent arthrodesis and the other is still receiving antibiotics under pathologist directions. In both patients there was a great amount of bone absorption and soft tissue necrosis around the implant. For patients of the third group complete eradication was achieved. Finally, for the 2 patients of the forth group, periods of exacerbation and remission of the infection exist, with good and poor quality of life, respectively. Conclusions: The treatment protocol that we apply was based on the clinical manifestations of the infection and was successful in most cases. Bone absorption, tissue necrosis and microorganism resistance are bad prognostic factors

Purpose: Infection after resection and total knee arthoplasty for malignant bone tumours in children is a serious complication which may compromise limb salvage. The purpose of this work was to study the aetiology, treatment and prognosis of this event. Material and methods: Among the 169 total knee arthroplasties performed for malignant bone tumours between 1981 and 1999, we selected 17 patients meeting the following criteria: proven infection with identified germ on deep samples or presence of a fistula more than two years after surgery. All of the patients had osteogenic sarcomas (excluding Ewing sarcomas which account for 30% of the tumours in this localisation). The bone tumour involved the femur (n=11) or the tibia (n=6) and required extraarticular (n=14) or transarticular (n=2) resection. Infections were primary (n=9) developing after the first operation, or secondary (n=8) to surgical revision in six, joint wound in one, or haematogeneous dissemination in one patient. The causal germ was identified in thirteen patients (76%) and was a staphylococcus in all cases. Treatment included systemic antibiotics and lavage (n=10), one-procedure change in prosthesis (n=3), removal of the implant with replacement by a spacer (n=2), surgical abstention (n=2), or amputation (n=1). Results: Mean follow-up was eight years (2 – 16 years). On the average, treatment of infection lasted 51 months and required a 3.9 surgical interventions. At last follow-up, infection was considered cured in 70% of the patients who were free of clinical or laboratory signs of infection without antibiotics for at least one year. The arthroplasty could be preserved in one-third of the cases (22% of the primary infections and 50% of the secondary infections). Another treatment, arthrodesis (n=6), Borggreve procedure (n=1), or amputation (n=4), was given in the other two-thirds. Discussion: The 10% complication rate observed here is in agreement with data in the literature. Development of primary infection is influenced more by the histology of the tumour and the presence of skin wounds (methotrexate) than by tumour site or type of resection. The diagnosis of primary infection is made late, often at the end of the postoperative chemotherapy protocol. Changing the implant is the ideal treatment. Secondary infection is characteristically less difficult to diagnose; infection is recognised earlier and the chances of preserving the implant are better

Aims

Debridement, antibiotics, and implant retention (DAIR) remains one option for the treatment of acute periprosthetic joint infection (PJI) despite imperfect success rates. Intraosseous (IO) administration of vancomycin results in significantly increased local bone and tissue concentrations compared to systemic antibiotics alone. The purpose of this study was to evaluate if the addition of a single dose of IO regional antibiotics to our protocol at the time of DAIR would improve outcomes.

There are now a number of controlled prospective trials comparing the advantages of unicompartmental arthroplasty versus total knee replacement (Rougraff 1991, Lawrencin 1991, Newman 1998, and Price 2000). These studies all favour unicompartmental arthroplasty over total knee replacement in terms of the following. The kinematics of uncompartmental arthroplasty are better and more normal for the surgery retains both cruciate ligaments with proprioceptive input. The range of motion tends to be greater in the unicompartmental group and the function better. This is especially true of demanding activities such as ascending and descending stairs, and has been shown using gait study analysis (O’Connor 1986). The pain relief is as good, or better, with unicompartmental arthroplasty in these studies when compared to total knee replacement, and in particular there is “a better feel” with unicompartmental arthroplasty. The complications with the smaller procedure tend to be less frequent and severe and the recovery more rapid, with a potential benefit allowing for a lower cost. There are however certain disadvantages encountered in using unicompartmental arthroplasty when compared to total knee replacement. In general there is a higher revision rate with the unicompartmental arthroplasty and this is particularly borne out in the Swedish Knee Arthroplasty Register. Using the strict criteria of Insal/Stern they suggest an incidence of 1:20 patients suitable for unicompartmental arthroplasty, and with such small numbers it is hardly surprising that there is a higher complication rate. The advantages of unicompartmental arthroplasty in the young remains controversial. In particular there are few comparative studies (Broughton and Newman 1988). In a small study from Oxford we have found that the pain relief and function in the unicompartmental arthroplasty group were substantially better with an age match comparison group using a patient based question score (The Oxford Knee Score 0–48). We sent the Oxford questionnaire to the HTO patients of the main proponent of osteotomy surgery in the UK, who has devoted a lifetime to perfecting the art of osteotomy surgery. These patients represent the “best case scenario” and his patients at five year follow up scored 27/48 on the Oxford Knee Score. Age match group of young uni-compartmental arthroplasty patients scored 38. Comparison of total knee replacement group would score 35, and it is of interest to note that those patients revised from a failed high tibial osteotomy to a total knee replacement raised their scores from 27 to 33. There are of course disadvantages comparing unicompartmental arthroplasty and high tibial osteotomy in the young. The main disadvantages that artificial material is implanted and there is the potential for infection. What remains debatable and controversial is the outcome of procedures when converting them to a total knee replacement. In terms of 10 year survivorship most of the published literature suggests that with high tibial osteotomy there is a two-thirds survivorship, one-third being converted to a total knee replacement by 10 years (range 51% to 80%) (Naudie 1999, Coventry 1993, Rudan 1991). The similar 10 year survivorship of unicompartmental arthroplasty in patients under 65 years is in the order of 80%. This is borne out in the Swedish Knee Registry. In general the problem with unicompartmental arthroplasty seems to centre around a higher revision rate, and faced with this problem there are a number of solutions. One can accept this and abandon the procedure, which has happened until recently in the United States. One can suggest that a unicompartmental arthroplasty is used as a pre-knee replacement, which has been forwarded by Repicci in the States. Alternatively one can try to minimise the failure rate by employing an implant with very good wear characteristics, one can concentrate on appropriate indications and one can define an accurate reproducible technique. One can seek to achieve a survival rate that is similar to that of the best total knee replacement. The Oxford unicompartmental knee replacement was deigned first by Goodfellow and O’Connor 25 years ago. It employs a spherical femoral component articulating on a flat tibial component. There is a fully mobile bearing, which is unconstrained. This bearing is fully congruent in all positions, which minimises wear. In two published retrieval studies (Argenson and Psychoyios) 10 year wear rate was 0.03mm per year. In those cases with no impingement the rate was 0.01mm per year. There was no correlation with thickness and we now feel comfortable advising a 3.5mm bearing for long term survivorship. The indications for unicompartmental arthroplasty in essence centre around medial compartment osteoarthritis with a functionally intact ACL. Some superficial damage to the ligament is acceptable, but in essence the structure needs to be intact to be functioning. There needs to be a correctable varus deformity with full thickness lateral compartment articular cartilage and this is best demonstrated on stress x-ray. A fixed flexion deformity of less than 15° is usual and employing the above indications we find that a unicompartmental arthroplasty is suitable for 1:4 knees presenting with osteoarthritis. We do not feel that the state of the patellofemoral joint is a contraindication to unicompartmental arthroplasty. We have significant evidence to corroborate this statement. In Mr Goodfellow’s published series in 1998 the state of the patellofemoral joint and the clinical results did not correlate. The study by Weale (1999) there was no progression of patellofemoral osteoarthritis over 10 years. On the Swedish Registry there have been no cited revisions for progression of patellofemoral arthritis. The age and the activity of the patient does not seem to be an obvious contraindication. In particular in the old and unfit using the minimal invasive approach there is a low morbidity, with all its attendant advantages. In the young patient (less than 50 years), the 10 year survivorship is 92% in two published series (Murray et al 1998 and Price 2000). The published 10 year results of the designers patient (Murray et al 1998) details the follow up of 144 unicompartmental arthroplasties with a 10 year survivorship. At 10 years there were 34 knees at risk giving a 98% 10 year survivorship 95%, confidence levels 93–100%. There was one case lost to follow up giving a worse case scenario of 97%. Of much more relevance concerns an independent series from Sweden (Svard et al 2001). These series is of 420 Oxford unicompartmental arthroplasties from a single centre performed by four surgeons. None lost to follow up. A 10+ year follow up involved 122 Oxford unis reviewed, with 92% good or excellent HSS scores. The 15 year survivorship was 94% with confidence levels 86 to 100%, there were none lost to follow up so the 15 year worse case scenario was 94%. This is better than fixed bearing unis and as good as the best total. The Swedish Knee Arthoplasty Register however gave a different picture, and was published in 1995 (Lewald et al), reported poor early results with no learning curve and advised that the difficult implant should not be used. We in fact have gained data from 944 rather than 699 from the register. It concluded that at these centres they had very reasonable results, but one or two centres had catastrophically poor results, in the order of 30% failure. We can only conclude that these poor results were due to inappropriate indications or technique. More recently in January 2001 Robertson et al have published an update of the Swedish Knee Arthroplasty Register citing good to excellent results in those centres performing more than 23 Oxford unicompartmental arthroplasties a year. Good results were possible, but there is a definite learning curve. The phase 3 tradition of the Oxford was introduced in 1998. The aim of this introduction was to make the operation simpler and more consistent. We have consistently employed a minimally invasive approach, but we have sought to keep the advantages of phase 2 Oxford unicompartmental arthroplasty. In effect there has been minor modifications to the instruments with an increased range of sizes. Our early phase 3 results, published in 1999 (Price et al) have compared the early recovery. This is the time taken to functional recovery, by which time the patient is ready for discharge. We compared the first 40 minimals with the last 20 opens and used 40 knee replacements taken as controls performed at the same time. We have shown that the minimally invasive unis recover three times faster than the totals (p< 0.001) and twice as fast as the open unis (p< 0.001). Finally our one year follow up of the first 58 phase 3 Oxford unicompartmental arthroplasties reveal increase in the mean flexion from pre-operative 123° to postoperative 135°. A high proportion of the patients gained at least 130° of flexion and 50% were 140+. A mean AKS score rose from a pre of 37 to one year of 98. The AKS function score raised from a pre 53 to one year 94, with a very high proportion of patients scoring 95+ score out of 100 on the AKS. In summary unicompartmental arthroplasties offer many potential advantages over TKR in terms of:. - Recovery, function. - The best long term results of uni (Oxford) are now as good as best TKR. - Unis in general are technically demanding and there is a definite learning curve

INTRODUCTION. Nowadays, longevity of total knee arthroplasties is very acceptable. Survivorship analyses demonstrate a success in a range of 80% to more than 95% over a period of more than ten years (1–4). However, long-term results largely depend, amongst other factors, on restoration of physiological alignment of the lower limb (5–11). Jeffery et al. (12) reported a three percent loosening rate over eight years when knees were correctly aligned whereas insufficient alignment lead to prosthetic loosening in 24 percent. Rand and Coventry (13) found a 90 percent survivorship rate at ten years when the mechanical axis was aligned in a range from nought to four degrees of valgus. Valgus position of more than four degrees or varus alignment resulted in only 71 percent and 73 percent of survivorship respectively. Recently, computer aided instrumentation systems (14,15) became available and preliminary results of small series were reported (16–17). The purpose of this study was to assess the accuracy of computer integrated instrumentation for knee alignment. MATERIAL AND METHOD. The OrthoPilot. ®. represents a computer controlled image supported alignment system. A 3-D Optotrak™ camera localizes infra-red diodes fixed to rigid bodies within the surgical field. Thereby a spatial coordinate reference system is provided. The localizer is linked to a UNIX work station which performs the operative protocol using a graphical interface and a foot pedal. The rigid bodies are fixed to the bones by bicortical screws. An intraoperative kinematic analysis and various additional landmarks lead to definition of the centres of hip, ankle and knee joint and sizing of endoprosthetic components. With the use of LED-equipped alignment instruments the femoral and tibial resection planes are determined. The OrthoPilot. ®. navigation system is not dependant on CT data and no additional preoperative planning is therefore necessary. A prospective comparative multicentre study in five institutions, four in Germany and one in France, was carried out. 821 patients with primary tricompartimental knee arthroplasty using the SEARCH LC knee (B|Braun AESCULAP) were included in the study. The OrthoPilot. ®. Navigation system was used in 555 cases and 266 knees were implanted with the use of conventional instrumentation. At the three months follow-up alignment was assessed using standardized one leg stance radiographs with regard to the mechanical axis and the femoral and tibial angels in the coronal plane. For the lateral femoral and tibial angels standard lateral x-rays were used. Prosthetic alignment was verified by an independent observer. RESULTS. The radiographically assessed results were subdivided into three groups. An error of ± one degree in the radiographical measurements and small deviations caused by the play of surgical instruments have to be considered. With respect to the femoral and tibial angels in the ap and lateral view the group of very good clinical results was, therefore, defined in the range between ninty degrees and ± two degrees. Deviations of three and four degrees from the optimum were classified as being clinically acceptable. Aberrations of more than four degrees were classified as outliers. When measuring the mechanical axis deviations from fully precise femoral and tibial angels may add up. For this reason zero degrees ± three degrees were rated as a very good result, deviations of four to five degrees were considered to be acceptable and alignment beyond five degrees from the optimum was classified as an unsatisfactory result. Mechanical axis:. 35. 2% of the navigated cases were aligned at exactly zero degrees. This was achieved in only 24. 4% of the manual cases. 88. 6% of cases using navigation and 72. 2% in the manual group showed zero degrees and varus or valgus angles of up to three degrees. 8. 9% and 18. 1% of cases respectively showed deviations of four or five degrees of valgus or varus alignment representing an acceptable clinical result. In only 2. 5% of the navigation group aberrations of more than five degrees occurred. The rate of dissatisfying results was 9. 8% in the manual group. Femoral axis (coronal plane):. In the navigation group 48. 1% of cases showed an alignment at exactly 90 degrees which was the case in only 33. 5% of the control group. Altogether, in 89. 4% of the navigated cases a very good result was observed. In the conventionally instrumented cases only 77. 1% very good results were found. There were 1. 6% outliers beyond the limits of four degrees in the navigation group in comparison to 4. 9% amongst the control cases. Femoral axis (sagittal plane):. Very good results with up to two degrees of deviation from a ninety degree position were obtained in 75. 5% of navigated cases and 70. 7% of manual cases. 37. 3% and 34. 6% respectively showed an ideal alignment of exactly ninety degrees. Unsatisfactory results were observed in 9. 5% of the navigated cases and 9. 4% of the manual cases. Tibial axis (coronal plane):. 58. 7% of the computer assisted and 40. 6% of the reference cases were exactly aligned at rectangles. All in all, in 91. 9% navigated and only 83. 5% manual cases a very good result was obtained. Only 1. 1% outliers had to be observed in the navigation group whereas 3. 4% unsatisfactory results were registered with manual technique. Tibial axis (sagittal plane):. 44. 3% of the navigated cases and only 26. 7% of cases in the control group were aligned perpendicular to the dorsal tibial cortex, thus showing no posterior slope. Altogether, 81. 3% could be classified as very good clinical results in the computer assisted group. The corresponding rate of the manual group was 69. 9%. Equivalent values of 8. 6% in the navigation group and 8. 3% in the reference group were registered beyond the limits of four degrees deviation. The additional operation time for the use of the navigation system is calculated between eight and ten minutes after having passed through the learning curve. CONCLUSIONS. Knee navigation facilitates proper alignment of endoprosthetic components and with the use of the Ortho-Pilot. ®. system results are clearly more favourable in comparison to conventional instrumentation technique. In addition, the data obtained from literature demonstrate that the use of this navigation system contributes to reducing outliers in number. With the learning curve the OrthoPilot. ®. alignment system proved to gain in reliability. Deviations from perfect alignment are still difficult to be classified into surgical or technical deficiencies. Many technical and software improvements which were introduced in the meantime will, in addition, contribute to reliability and time saving. Comparative studies with different navigation systems are not yet available. They might allow an even more profound insight into the possibilities and advantages or disadvantages of computer assisted knee alignment. LITERATURE. (1) Knutson K, Lindstrand A, Lidgren L. Survival of knee arthroplasties, a nation-wide multicenter investigation of 8000 cases. J Bone Joint Surg. 1986; 68B: 795-803 . (2) Scuderi GR, Insall JN, Windsor RE, Moran MC. Survivorship of cemented knee replacement. J Bone Joint Surg. 1989; 798-409 . (3) Nafei A, Kristensen O, Knudson HM, Hvid I, Jensen J. Survivorship analysis of cemented total condylar knee arthoplasty. J Arthoplasty 11, 1996;07-10 . (4) Ranawat CS, Flynn WF, Saddler S, Hansraj KH, Maynhard MJ. Long-term results of total condylar knee arthroplasty. A 15-years survivorship study. Clin Orthop 1993; 286:94-102 . (5) Lotke PA, Ecker ML. Influence of positioning of prosthesis in total knee replacement. J Bone Joint Surg 1977;59-A:77-79 . (6) Hood RW, Vanni M, Insall JN. The correction of knee alignment in 225 consecutive total condylar knee replacements. Clin Orthop 1981;160:94-105 . (7) Bargren JH, Blaha JD, Freeman MAR. Alignment in total knee arthroplasty. Clin Orthop 1983;173:178-183. . (8) Hvid I, Nielsen S. Total condylar knee arthroplasty. Acta Orthop Scand 1984;55:160-165 . (9) Tew M, Waugh W. Tibial-femoral alignment and the results of knee replacement. J Bone Joint Surg 1985;67-B:551-556 . (10) Jonsson B, Astrom J. Alignment and long-term clinical results of a semi-constrained knee prosthesis. Clin Orthop 1988;226:124-128 . (11) Ritter MA, Faris PM, Keating EM, Meding JB. Postoperative alignment of total knee replacement its effect on survival. Clin Orthop 1994;299:153-156 . (12) Jeffery RS, Morris RW, Denham RA. Coronal alignment after total knee replacement. J Bone Joint Surg 1991;73-B:709-714 . (13) Rand JA, Coventry MB. Ten-year evaluation of geometric total knee arthroplasty. 1988;232:168-173 . (14) Leitner F, Picard F, Minfelde R, Schulz HJ, Clinquin P, Saragaglia D. Computer assisted knee surgical total replacement. In: CVRMed-MRCAS. Troccaz J, Grimson E, Mösges R (Eds). 1997; 630-638, Springer . (15) Delp SL, Stulberg SD, Davies BL, Picard F, Leitner F. Computer assisted knee replacement. Clin Orthop 1998; 354:49-56 . (16) Picard F, Saragaglia D, Montbarbon E, Chaussard C, Leitner F, Raoult O. Computer assisted knee arthroplasty - preliminary clinical results with the Ortho-Pilot System. Abstract, 4th International CAOS Symposium, Davos, Switzerland, 1999 . (17) Miehlke RK, Clemens U, Jens J-H, Kershally S. Navigation in der Knieendoprothetik - vorläufige klinische Erfahrungen und prospektiv vergleichende Studie gegenüber konventioneller Implantationstechnik, Z Orthop 2001; 139: 109-116

Objectives

Wound complications are reported in up to 10% hip and knee arthroplasties and there is a proven association between wound complications and deep prosthetic infections. In this randomised controlled trial (RCT) we explore the potential benefits of a portable, single use, incisional negative pressure wound therapy dressing (iNPWTd) on wound exudate, length of stay (LOS), wound complications, dressing changes and cost-effectiveness following total hip and knee arthroplasties.