Abstract

Background

Surgical simulators allow learner-focussed skills training, in controllable and reproducible environments suitable for assessment.

Every country has its own criteria for consent. In most, a written consent form is used to reflect patient understanding and permision for the procedure to happen.

While oral consent has as much legal sway as the written consent form, the presence of a signature acts as proof of discussion. All European hospitals should have a 100% compliance with patient’s signing consent forms, but their completion is often incomplete and inaccurate, have errors of omission and have lead to litigation, poor patient understanding and recall.

We (along witht the BOA) introduce an computer programme of procedure specific orthopaedic consent forms. They have been created for most common elective and trauma operations. The forms follow the UK Department of Health guidelines on consent and contain a brief explanation of the procedure, offer alternative therapies/consequences of not having the procedure (where appropriate), the serious risks and commonly occurring complications. They are written in layman’s English (aimed at a reading age of 14 years). Preliminary trials have also shown the time taken to print and complete a pre-designed form is much less than that of the current handwritten form, reducing errors of omission whilst still allowing discussion with the patient.

The forms are currently available as word documents from an easily navigable website. With a view towards European usage, the forms can be easily translated to other languages at minimal cost.

With support from the British Orthopaedic Association (BOA), the BOA medico-legal committee, the specialist societies and consultant users (via the website) we hope that the project will continue to evolve with a greater selection of procedural consent forms becoming available.

It is believed, from the evidence available, that this approach should decrease the incidence of patient misunderstanding, and the potential risk of successful litigation, while encouraging better communication between patients and surgeons.

Purpose: To correlate arthroscopic appearances of the anterior and posterior meniscofemoral ligaments (aMFL and pMFL respectively) with their appearances on magnetic resonance imaging.

Methods: 50 patients underwent MRI scanning of their knees for a variety of suspected pathologies. The radiological presence or absence of the MFLs was assessed by examination of sequential coronal and sagittal T2 weighted MRI scans. Arthroscopic examination of the knees was subsequently performed, during which the MFLs were identified using several anatomical cues. These included their femoral and meniscal attachments, their obliquity relative to the PCL, and the meniscal “tug test”. Identification was classed as “easy” or “hard” by the operating surgeon.

Results: From 50 knees 44 (88%) aMFLs and 30 (60%) pMFLs were identified on MRI scanning, whilst 47 (94%) aMFLs and 5 (10%) pMFLs were identified arthroscopically. Identification of the presence or absence of the aMFL was classed as easy in 47 (94%), whilst the pMFL was easy to identify in only 5 (10%) of knees, of which 3 (6%) had a ruptured PCL. Using arthroscopy of the aMFL as the gold standard, the sensitivity and specificity of MRI in detecting the aMFL were 94% and 75% respectively. Equivalent values for the pMFL were not calculated due to the difficulty of identifying the pMFL arthroscopically. Thus, with the exception of PCL-deficient knees, it was felt that many pMFLs were missed due to difficulties in identification through anterior portals.

Conclusions: This is the first study correlating the MRI appearances of the MFLs with arthroscopic findings. MRI is relatively sensitive in identifying the aMFL, but its accuracy in identifying the pMFL remains undetermined. Accurate identification of the MFLs at MRI is of value when assessing the status of the PCL, as these ligaments may contribute to stabilising the PCL-deficient knee.

Aim: To test the hypothesis that the meniscofemoral ligaments (MFLs) make a significant contribution to resisting anteroposterior and rotatory laxity of the posterior cruciate ligament (PCL) deficient knee.

Methods: The anterior and posterior MFLs of eight cadaveric knees were identified using previously described dissection techniques [1], which were shown not to affect overall knee stability in control studies. These specimens were tested for anteroposterior and rotatory laxity in a materials testing machine. The posterior cruciate ligament was then divided, followed by division of the MFLs. Laxity results were obtained for intact, PCL-deficient and PCL/MFL-deficient knees. Results were analysed using repeated measures analysis of variance and paired t tests.

Results: Division of the MFLs in the PCL-deficient knee significantly increased posterior laxity between 15o and 90o of flexion (p< 0.01). Force/displacement measurements revealed that, at 90° flexion, the MFLs contributed to 28% of total resistance to posterior drawer in the intact knee and 70% in the PCL-deficient knee (p< 0.01). There was no effect on rotatory laxity (p> 0.2).

Discussion: Previous studies have demonstrated a high prevalence of the MFLs in knees1 and that these ligaments have a strength similar to the posterior fibre bundle of the PCL [2]. The current in vitro study suggests that they contribute to overall resistance to posterior drawer, especially in the PCL-deficient knee. If this is confirmed in vivo, patients with PCL injuries may have a reduced posterior drawer sign if their MFLs are intact, and this may result in a more stable knee. Thus the MFLs should be accurately identified and assessed during MRI scanning and arthroscopy [3].

Conclusion: This is the first study demonstrating a function for the MFLs as secondary restraints to posterior drawer in the PCL-deficient knee. The integrity of these structures should be assessed during both MRI scanning and arthroscopy of PCL-injured patients, as this may affect the diagnosis and management of such injuries.

Introduction: Accurate size-matching of meniscal allografts is essential to maintain tibiofemoral congruity, and therefore function, especially when the surgical technique of using a bony bridge is employed.

Methods of accurately assessing the required dimensions of an ideal meniscal allograft for each patient are limited. One popular method used is to choose the appropriate graft according to the bony tibial plateau dimensions of the patient, as determined from plain radiographs.

Aims: To correlate meniscal dimensions with the bony dimensions of donor tibial plateaus.

Methods: 22 left and right pairs of donor tibial plateaus with intact meniscal allografts were obtained, giving a total of 88 individual meniscal allografts. Using a digital micrometer, the following meniscal dimensions were measured: anteroposterior length, medial-lateral width, and the radial width at the mid-point of the meniscal body. Peripheral circumference was measured using flexible steel wire. Medial and lateral bony tibial plateau width and length, and total plateau width were also recorded.

Linear regression analysis was used to obtain a formula, relating each meniscal dimension to the various bony plateau measurements. The resulting equations were used to calculate an expected meniscal dimension from the measured plateau dimensions, and this was compared to the size of the actual dimension measured.

Results: The magnitude of the meniscal dimensions measured approximately fitted a normal distribution amongst all the specimens studied. The tibial plateau widths ranged from 69.2mm to 88.4mm (mean 78.5mm, s.d. 5.4mm), a 28% difference. The mean difference between meniscal measurements between the left and right knee of each pair was 7.3%. However, the greatest individual difference observed was 41.8%.

The mean percentage error between meniscal dimensions calculated from specific compartmental tibial plateau dimensions, and the actual measured meniscal dimensions was 5.3% (s.d. 4.1%). When using just total bony tibial plateau width to calculate meniscal dimensions, the percentage error was 6.2% (s.d. 4.9%). This difference was not statistically significant. The maximum error between calculated and actual meniscal dimensions was 32%.

Conclusions: This anatomical study shows that the use of plateau dimensions as a determinant for the sizing of meniscal allografts can be used to predict meniscal dimensions. However, mean errors are in the region of 5% – 6%, and can be as high as 32%. The potential mechanical effects of such graft to host size mismatching must be carefully borne in mind.

The aim of this study was to determine the function of the meniscofemoral ligament in the cranio-caudal and rotatory laxity of the ovine stifle.

Twenty fresh cadaveric ovine stifles were harvested from fully mature sheep, average weight 25kg. The joint was denuded of its muscular attachments leaving the capsule, including the patella and patellar tendon undisturbed. The femur and tibia were divided 10 cm from the joint line, positioned in cylindrical pots, and secured in polymethylmethacrylate bone cement. The stifles were tested in a four-degree-of-freedom rig positioned in an Instron materials testing machine. This allowed unconstrained coupled tibial rotations and translations during application of cranial (anterior) and caudal (posterior) draw forces. Forces up to a maximum of 100Nm were applied in the anterior and posterior directions, and the resultant translations were measured. These parameters were assessed at 30, 60, 90, and 110 degrees of flexion in ten intact stifles. Similar measurements were carried out after division of the caudal (posterior) cruciate ligament, followed by division of the meniscofemoral ligament. The sequence of division was reversed for a further ten stifles.

Division of the meniscofemoral ligament resulted in an 18–38% increase in posterior translation at all angles of flexion, both in the intact and in the caudal cruciate ligament-deficient stifle (p< 0.05). There was no significant increase in anterior translation. This effect was largest with the joint relatively extended (at 30°). Division of the meniscofemoral ligament also resulted in a 5–32% increase in internal rotation of the tibia after application of a 6Nm torque in the caudal cruciate-deficient knee. This was significant at 30° and 110° flexion (p< 0.05).

The meniscofemoral ligament is a significant secondary restraint in resisting the posterior draw and internal tibial rotation in the sheep stifle joint. This is the first study demonstrating a functional role for this structure in any animal. Its counterpart in the human is the posterior meniscofemoral ligament of Wrisberg. Several studies have demonstrated similarities between the sheep stifle and the human knee. Confirmation of a similar role for the ligament of Wrisberg in the human knee would have a significant bearing on the prognosis and management of the posterior cruciate ligament injured knee.

The objective of this study was to examine patients’ use of the Internet to obtain medical information, their opinions on the quality of medical Web sites and their attitudes towards Internet-based consultations.

The study made use of a questionnaire given to 398 patients, aged 10 to 95 years (mean 55 years), visiting the orthopaedic outpatient clinics of a London district general hospital over a 2 week period. The major outcome measures were; 1) the rate of Internet use by patients, 2) the perception of the quality of medical websites, 3) future intentions and attitudes towards internet-based consultations, and 4) concurrence between information obtained from Web sites and advice given by the orthopaedic surgeon in the clinic. Results were considered significant at p< 0.05. The Chi² test was used to compare proportions. Spearman’s correlation coefficients were used to quantify correlation.

From 369 respondents (response rate 91%), 55.3% of patients had accessed the Internet. Of these 52.0% had obtained medical information from this source. Access was linearly correlated with age (r² =0.975, p< 0.01) and was also related to social status. Of the 12.3% of patients who had researched their particular orthopaedic condition, 20% reported that the advice received from the surgeon in the clinical contradicted that obtained from the Internet. A total of 37.5% of patients would undergo an Internet-based consultation, whilst a further 25.5% would consider this, depending on the medical condition in question.

This is the first detailed UK study examining patient attitude towards Web-based medical learning. Over half of the patients were willing to access the Internet for medical information, with younger patients more likely to undertake this activity. As the commercial advantages of a captive patient population become apparent, there is the potential for inaccurate or misleading information, that has not undergone peer review, to be disseminated over the Internet The increased use of medical Websites by patients raised important issues regarding the need for quality control, which orthopaedic surgeons and their institutions both need to address. This also impacts significantly upon the changing nature of the surgeon-patient relationship.