Aims. The aim of this study was to determine the risk of tibial eminence avulsion intraoperatively for bi-unicondylar knee arthroplasty (Bi-UKA), with consideration of the effect of implant positioning, overstuffing, and sex, compared to the risk for isolated medial unicondylar knee arthroplasty (UKA-M) and bicruciate-retaining total knee arthroplasty (BCR-TKA). Methods. Two experimentally validated finite element models of tibia were implanted with UKA-M, Bi-UKA, and BCR-TKA. Intraoperative loads were applied through the condyles, anterior cruciate ligament (ACL), medial collateral ligament (MCL), and lateral collateral ligament (LCL), and the risk of fracture (ROF) was evaluated in the spine as the ratio of the 95. th. percentile maximum principal elastic strains over the tensile yield strain of proximal tibial bone. Results. Peak tensile strains occurred on the anterior portion of the medial sagittal cut in all simulations. Lateral translation of the medial implant in Bi-UKA had the largest increase in ROF of any of the implant positions (43%). Overstuffing the joint by 2 mm had a much larger effect, resulting in a six-fold increase in ROF. Bi-UKA had ~10% increased ROF compared to UKA-M for both the male and female models, although the smaller, less dense female model had a 1.4 times greater ROF compared to the male model. Removal of anterior bone akin to BCR-TKA doubled ROF compared to Bi-UKA. Conclusion. Tibial eminence avulsion fracture has a similar risk associated with Bi-UKA to UKA-M. The risk is higher for smaller and less dense tibiae. To minimize risk, it is most important to avoid overstuffing the joint, followed by correctly positioning the medial implant, taking care not to narrow the bone island anteriorly. Cite this article: Bone Joint Res 2022;11(8):575–584

Aims. The anterior cruciate ligament (ACL) is known to have a poor wound healing capacity, whereas other ligaments outside of the knee joint capsule such as the medial collateral ligament (MCL) apparently heal more easily. Plasmin has been identified as a major component in the synovial fluid that varies among patients. The aim of this study was to test whether plasmin, a component of synovial fluid, could be a main factor responsible for the poor wound healing capacity of the ACL. Methods. The effects of increasing concentrations of plasmin (0, 0.1, 1, 10, and 50 µg/ml) onto the wound closing speed (WCS) of primary ACL-derived ligamentocytes (ACL-LCs) were tested using wound scratch assay and time-lapse phase-contrast microscopy. Additionally, relative expression changes (quantitative PCR (qPCR)) of major LC-relevant genes and catabolic genes were investigated. The positive controls were 10% fetal calf serum (FCS) and platelet-derived growth factor (PDGF). Results. WCS did not differ significantly among no plasmin versus each of the tested concentrations (six donors). The positive controls with PDGF and with FCS differed significantly from the negative controls. However, we found a trend demonstrating that higher plasmin concentrations up-regulate the expression of matrix metalloproteinase 13 (MMP13), 3 (MMP3), and tenomodulin (TNMD). Conclusion. The clinical relevance of this study is the possibility that it is not solely the plasmin, but also additional factors in the synovial fluid of the knee, that may be responsible for the poor healing capacity of the ACL. Cite this article: Bone Joint Res 2020;9(9):543–553

Aims. Inadvertent soft tissue damage caused by the oscillating saw during total knee arthroplasty (TKA) occurs when the sawblade passes beyond the bony boundaries into the soft tissue. The primary objective of this study is to assess the risk of inadvertent soft tissue damage during jig-based TKA by evaluating the excursion of the oscillating saw past the bony boundaries. The second objective is the investigation of the relation between this excursion and the surgeon’s experience level. Methods. A conventional jig-based TKA procedure with medial parapatellar approach was performed on 12 cadaveric knees by three experienced surgeons and three residents. During the proximal tibial resection, the motion of the oscillating saw with respect to the tibia was recorded. The distance of the outer point of this cutting portion to the edge of the bone was defined as the excursion of the oscillating saw. The excursion of the sawblade was evaluated in six zones containing the following structures: medial collateral ligament (MCL), posteromedial corner (PMC), iliotibial band (ITB), lateral collateral ligament (LCL), popliteus tendon (PopT), and neurovascular bundle (NVB). Results. The mean 75. th. percentile value of the excursion of all cases was mean 2.8 mm (SD 2.9) for the MCL zone, mean 4.8 mm (SD 5.9) for the PMC zone, mean 3.4 mm (SD 2.0) for the ITB zone, mean 6.3 mm (SD 4.8) for the LCL zone, mean 4.9 mm (SD 5.7) for the PopT zone, and mean 6.1 mm (SD 3.9) for the NVB zone. Experienced surgeons had a significantly lower excursion than residents. Conclusion. This study showed that the oscillating saw significantly passes the edge of the bone during the tibial resection in TKA, even in experienced hands. While reported neurovascular complications in TKA are rare, direct injury to the capsule and stabilizing structures around the knee is a consequence of the use of a hand-held oscillating saw when making the tibial cut. Cite this article: Bone Joint J 2020;102-B(10):1324–1330

Most injuries to the medial collateral ligament (MCL) heal well after conservative treatment. We have identified a subgroup of injuries to the deep portion of the MCL which is refractory to conservative treatment and causes persistant symptoms. They usually occur in high-level football players and may require surgical repair. We describe a consecutive series of 17 men with a mean age of 29 years (18 to 44) who were all engaged in high levels of sport. Following a minor injury to the MCL there was persistent tenderness at the site of the proximal attachment of the deep MCL. It could be precipitated by rapid external rotation at the knee by clinical testing or during sport. The mean time from injury to presentation was 23.6 weeks (10 to 79) and none of the patients had responded to conservative treatment. The surgical finding was a failure of healing of a tear of the deep MCL at its femoral origin which could be repaired. After a period of postoperative protective bracing and subsequent rehabilitation the outcome was good. All the patients returned to their sports and remained asymptomatic at a mean of 48 weeks (28 to 60) post-operatively. Recognition of this subgroup is important since the clinical features, the course of recovery and surgical requirement differ from those of most injuries to the MCL

We present the operative technique and clinical results of concomitant reconstruction of the medial collateral ligament (MCL) and the posterior oblique ligament for medial instability of the knee using autogenous semitendinosus tendon with preservation of the tibial attachment. The semitendinosus tendon graft between the screw on the medial epicondyle and the tibial attachment of the graft was overlapped by the MCL, while the graft between the screw and the insertion of the direct head of the semimembranosus tendon was overlapped by the central arm of the posterior oblique ligament. Assessment was by stress radiograph and the Lysholm knee scoring scale. After a mean follow-up of 52.6 months (25 to 92), the medial joint opening of the knee was within 2 mm in 22 of 24 patients. The mean Lysholm score was 91.9 (80 to 100). Concomitant reconstruction of the MCL and posterior oblique ligament using autogenous semitendinosus tendon provides a good solution to medial instability

Objectives. Malrotation of the femoral component can result in post-operative complications in total knee arthroplasty (TKA), including patellar maltracking. Therefore, we used computational simulation to investigate the influence of femoral malrotation on contact stresses on the polyethylene (PE) insert and on the patellar button as well as on the forces on the collateral ligaments. Materials and Methods. Validated finite element (FE) models, for internal and external malrotations from 0° to 10° with regard to the neutral position, were developed to evaluate the effect of malrotation on the femoral component in TKA. Femoral malrotation in TKA on the knee joint was simulated in walking stance-phase gait and squat loading conditions. Results. Contact stress on the medial side of the PE insert increased with internal femoral malrotation and decreased with external femoral malrotation in both stance-phase gait and squat loading conditions. There was an opposite trend in the lateral side of the PE insert case. Contact stress on the patellar button increased with internal femoral malrotation and decreased with external femoral malrotation in both stance-phase gait and squat loading conditions. In particular, contact stress on the patellar button increased by 98% with internal malrotation of 10° in the squat loading condition. The force on the medial collateral ligament (MCL) and the lateral collateral ligament (LCL) increased with internal and external femoral malrotations, respectively. Conclusions. These findings provide support for orthopaedic surgeons to determine a more accurate femoral component alignment in order to reduce post-operative PE problems. Cite this article: K-T. Kang, Y-G. Koh, J. Son, O-R. Kwon, C. Baek, S. H. Jung, K. K. Park. Measuring the effect of femoral malrotation on knee joint biomechanics for total knee arthroplasty using computational simulation. Bone Joint Res 2016;5:552–559. DOI: 10.1302/2046-3758.511.BJR-2016-0107.R1

We have shown in a previous study that patients with combined lesions of the anterior cruciate (ACL) and medial collateral ligaments (MCL) had similar anteroposterior (AP) but greater valgus laxity at 30° after reconstruction of the ACL when compared with patients who had undergone reconstruction of an isolated ACL injury. The present study investigated the same cohort of patients after a minimum of three years to evaluate whether the residual valgus laxity led to a poorer clinical outcome. Each patient had undergone an arthroscopic double-bundle ACL reconstruction using a semitendinosus-gracilis graft. In the combined ACL/MCL injury group, the grade II medial collateral ligament injury was not treated. At follow-up, AP laxity was measured using a KT-2000 arthrometer, while valgus laxity was evaluated with Telos valgus stress radiographs and compared with the uninjured knee. We evaluated clinical outcome scores, muscle girth and time to return to activities for the two groups. Valgus stress radiographs showed statistically significant greater mean medial joint opening in the reconstructed compared with the uninjured knees (1.7 mm (. sd. 0.9) versus 0.9 mm (. sd. 0.7), respectively, p = 0.013), while no statistically significant difference was found between the AP laxity and the other clinical parameters. Our results show that the residual valgus laxity does not affect AP laxity significantly at a minimum follow up of three years, suggesting that no additional surgical procedure is needed for the medial collateral ligament in combined lesions

We have reviewed the literature on the anatomy of the posteromedial peripheral ligamentous structures of the knee and found differing descriptions. Our aim was to clarify the differing descriptions with a simplified interpretation of the anatomy and its contribution to the stability of the knee. We dissected 20 fresh-frozen cadaver knees and the anatomy was recorded using video and still digital photography. The anatomy was described by dividing the medial collateral ligament (MCL) complex into thirds, from anterior to posterior and into superficial and deep layers. The main passive restraining structures of the posteromedial aspect of the knee were found to be superficial MCL (parallel, longitudinal fibres), the deep MCL and the posteromedial capsule (PMC). In the posterior third, the superficial and deep layers blend. Although there are oblique fibres (capsular condensations) running posterodistally from femur to tibia, no discrete ligament was seen. In extension, the PMC appears to be an important functional unit in restraining tibial internal rotation and valgus. Our aim was to clarify and possibly simplify the anatomy of the posteromedial structures. The information would serve as the basis for future biomechanical studies to investigate the contribution of the posteromedial structures to joint stability

We studied the stabilising effect of prosthetic replacement of the radial head and repair of the medial collateral ligament (MCL) after excision of the radial head and section of the MCL in five cadaver elbows. Division of the MCL increased valgus angulation (mean 3.9 ± 1.5°) and internal rotatory laxity (mean 5.3 ± 2.0°). Subsequent excision of the radial head allowed additional valgus (mean 11.1 ± 7.3°) and internal rotatory laxity (mean 5.7 ± 3.9°). Isolated replacement of the radial head reduced valgus laxity to the level before excision of the head, while internal rotatory laxity was still greater (2.8 ± 2.1°). Isolated repair of the MCL corrected internal rotatory laxity, but a slight increase in valgus laxity remained (mean 0.7 ± 0.6°). Combined replacement of the head and repair of the MCL restored stability completely. We conclude that the radial head is a constraint secondary to the MCL for both valgus displacement and internal rotation. Isolated repair of the ligament is superior to isolated prosthetic replacement and may be sufficient to restore valgus and internal rotatory stability after excision of the radial head in MCL-deficient elbows

Aims

Mid-level constraint designs for total knee arthroplasty (TKA) are intended to reduce coronal plane laxity. Our aims were to compare kinematics and ligament forces of the Zimmer Biomet Persona posterior-stabilized (PS) and mid-level designs in the coronal, sagittal, and axial planes under loads simulating clinical exams of the knee in a cadaver model.

The aim of mechanical alignment in total knee arthroplasty is to align all knees into a fixed neutral position, even though not all knees are the same. As a result, mechanical alignment often alters a patient’s constitutional alignment and joint line obliquity, resulting in soft-tissue imbalance. This annotation provides an overview of how the Coronal Plane Alignment of the Knee (CPAK) classification can be used to predict imbalance with mechanical alignment, and then offers practical guidance for bone balancing, minimizing the need for soft-tissue releases.

Cite this article: Bone Joint J 2024;106-B(6):525–531.

Aims

Cartilage injuries rarely heal spontaneously and often require surgical intervention, leading to the formation of biomechanically inferior fibrous tissue. This study aimed to evaluate the possible effect of amelogenin on the healing process of a large osteochondral injury (OCI) in a rat model.

Aims

There are concerns regarding complications and longevity of total elbow arthroplasty (TEA) in young patients, and the few previous publications are mainly limited to reports on linked elbow devices. We investigated the clinical outcome of unlinked TEA for patients aged less than 50 years with rheumatoid arthritis (RA).

Aims

The purpose of this study was to evaluate the relationships between the degree of injury to the medial and lateral collateral ligaments (MCL and LCL) and associated fractures in patients with a posterolateral dislocation of the elbow, using CT and MRI.

Aims

Anterior cruciate ligament (ACL) rupture commonly leads to post-traumatic osteoarthritis, regardless of surgical reconstruction. This study uses standing MRI to investigate changes in contact area, contact centroid location, and tibiofemoral alignment between ACL-injured knees and healthy controls, to examine the effect of ACL reconstruction on these parameters.

Aims

Surgeons commonly resect additional distal femur during primary total knee arthroplasty (TKA) to correct a flexion contracture, which leads to femoral joint line elevation. There is a paucity of data describing the effect of joint line elevation on mid-flexion stability and knee kinematics. Thus, the goal of this study was to quantify the effect of joint line elevation on mid-flexion laxity.

Aims

To evaluate the outcomes of terrible triad injuries (TTIs) in mid-term follow-up and determine whether surgical treatment of the radial head influences clinical and radiological outcomes.

Dissatisfaction following total knee arthroplasty is a well-documented phenomenon. Although many factors have been implicated, including modifiable and nonmodifiable patient factors, emphasis over the past decade has been on implant alignment and stability as both a cause of, and a solution to, this problem. Several alignment targets have evolved with a proliferation of techniques following the introduction of computer and robotic-assisted surgery. Mechanical alignment targets may achieve mechanically-sound alignment while ignoring the soft tissue envelope; kinematic alignment respects the soft tissue envelope while ignoring the mechanical environment. Functional alignment is proposed as a hybrid technique to allow mechanically-sound, soft tissue-friendly alignment targets to be identified and achieved.

Cite this article: Bone Joint J 2020;102-B(3):276–279.

Aims

The use of technology to assess balance and alignment during total knee surgery can provide an overload of numerical data to the surgeon. Meanwhile, this quantification holds the potential to clarify and guide the surgeon through the surgical decision process when selecting the appropriate bone recut or soft tissue adjustment when balancing a total knee. Therefore, this paper evaluates the potential of deploying supervised machine learning (ML) models to select a surgical correction based on patient-specific intra-operative assessments.

Aims

Dual plating of distal femoral fractures with medial and lateral implants has been performed to improve construct mechanics and alignment, in cases where isolated lateral plating would be insufficient. This may potentially compromise vascularity, paradoxically impairing healing. This study investigates effects of single versus dual plating on distal femoral vascularity.

Aims

Commonly performed unicompartmental knee arthroplasty (UKA) is not designed for the lateral compartment. Additionally, the anatomical medial and lateral tibial plateaus have asymmetrical geometries, with a slightly dished medial plateau and a convex lateral plateau. Therefore, this study aims to investigate the native knee kinematics with respect to the tibial insert design corresponding to the lateral femoral component.

Aims

The aim of this study was to evaluate the outcome of Monteggia-like lesions at midterm follow-up and to determine whether the surgical treatment of the radial head influences the clinical and radiological results.

Objectives

Unicompartmental knee arthroplasty (UKA) is one surgical option for treating symptomatic medial osteoarthritis. Clinical studies have shown the functional benefits of UKA; however, the optimal alignment of the tibial component is still debated. The purpose of this study was to evaluate the effects of tibial coronal and sagittal plane alignment in UKA on knee kinematics and cruciate ligament tension, using a musculoskeletal computer simulation.

Objectives

Unicompartmental knee arthroplasty (UKA) is an alternative to total knee arthroplasty for patients who require treatment of single-compartment osteoarthritis, especially for young patients. To satisfy this requirement, new patient-specific prosthetic designs have been introduced. The patient-specific UKA is designed on the basis of data from preoperative medical images. In general, knee implant design with increased conformity has been developed to provide lower contact stress and reduced wear on the tibial insert compared with flat knee designs. The different tibiofemoral conformity may provide designers the opportunity to address both wear and kinematic design goals simultaneously. The aim of this study was to evaluate wear prediction with respect to tibiofemoral conformity design in patient-specific UKA under gait loading conditions by using a previously validated computational wear method.

Aims

Between 15% and 20% of patients remain dissatisfied following total knee arthroplasty (TKA). The SAIPH knee system (MatOrtho, Surrey, United Kingdom) is a medial ball and socket TKA that has been designed to replicate native knee kinematics in order to maximize the range of movement, stability, and function. This system is being progressively introduced in a stepwise fashion, with this study reporting the mid-term clinical and radiological outcomes.

Aims

The crucial role of the radial head in the stability of the elbow in terrible triad injury is acknowledged. This retrospective study aims to compare the results of resection of a severely comminuted radial head with or without prosthetic arthroplasty as part of the reconstruction for this injury.

Aims

The results of kinematic total knee arthroplasty (KTKA) have been reported in terms of limb and component alignment parameters but not in terms of gap laxities and differentials. In kinematic alignment (KA), balance should reflect the asymmetrical balance of the normal knee, not the classic rectangular flexion and extension gaps sought with gap-balanced mechanical axis total knee arthroplasty (MATKA). This paper aims to address the following questions: 1) what factors determine coronal joint congruence as measured on standing radiographs?; 2) is flexion gap asymmetry produced with KA?; 3) does lateral flexion gap laxity affect outcomes?; 4) is lateral flexion gap laxity associated with lateral extension gap laxity?; and 5) can consistent ligament balance be produced without releases?

Aims

The aim of this study was to report the mid-term clinical outcome of cemented unlinked J-alumina ceramic elbow (JACE) arthroplasties when used in patients with rheumatoid arthritis (RA).

Objectives

Ligaments which heal spontaneously have a healing process that is similar to skin wound healing. Menopause impairs skin wound healing and may likewise impair ligament healing. Our purpose in this study was to investigate the effect of surgical menopause on ligament healing in a rabbit medial collateral ligament model.

Objectives

Malalignment of the tibial component could influence the long-term survival of a total knee arthroplasty (TKA). The object of this study was to investigate the biomechanical effect of varus and valgus malalignment on the tibial component under stance-phase gait cycle loading conditions.

Valgus knee deformity can present a number of unique surgical challenges for the total knee arthroplasty (TKA) surgeon. Understanding the typical patterns of bone and soft-tissue pathology in the valgus arthritic knee is critical for appropriate surgical planning. This review aims to provide the knee arthroplasty surgeon with an understanding of surgical management strategies for the treatment of valgus knee arthritis.

Lateral femoral and tibial deficiencies, contracted lateral soft tissues, attenuated medial soft tissues, and multiplanar deformities may all be present in the valgus arthritic knee. A number of classifications have been reported in order to guide surgical management, and a variety of surgical strategies have been described with satisfactory clinical results. Depending on the severity of the deformity, a variety of TKA implant designs may be appropriate for use.

Regardless of an operating surgeon’s preferred surgical strategy, adherence to a step-wise approach to deformity correction is advised.

Cite this article: Bone Joint J 2017;99-B(1 Supple A):60–4.

Obesity is a worldwide epidemic that has both economic and health implications of enormous consequence. The obese patients tend to have earlier symptoms related to osteoarthritis, more peri-operative medical problems, higher rates of infection and more technical difficulties intra-operatively following hip and knee arthroplasty. Nevertheless, these patients have good long-term clinical outcomes and implant survival rates and are often some of the most satisfied patients after joint arthroplasty. Therefore, obese patients should not be denied surgery based on their weight alone.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):3–5.

Aims

The purpose of this study was to report the experience of dynamic intraligamentary stabilisation (DIS) using the Ligamys device for the treatment of acute ruptures of the anterior cruciate ligament (ACL).

Aims

An evidence-based radiographic Decision Aid for meniscal-bearing unicompartmental knee arthroplasty (UKA) has been developed and this study investigates its performance at an independent centre.

New developments in osteotomy techniques and methods of fixation have caused a revival of interest of osteotomies around the knee. The current consensus on the indications, patient selection and the factors influencing the outcome after high tibial osteotomy is presented. This paper highlights recent research aimed at joint pressure redistribution, fixation stability and bone healing that has led to improved surgical techniques and a decrease of post-operative time to full weight-bearing.

Anatomical total knee arthroplasty alignment versus conventional mechanical alignment; or a combination?

Instability after total knee replacement (TKR) accounts for 10% to 22% of revision procedures. All patients who present for evaluation of instability require a thorough history to be taken and physical examination, as well as appropriate imaging. Deep periprosthetic infection must be ruled out by laboratory testing and an aspiration of the knee must be carried out. The three main categories of instability include flexion instability, extension instability (symmetric and asymmetric), and genu recurvatum. Most recently, the aetiologies contributing to, and surgical manoeuvres required to correct, flexion instability have been elucidated. While implant design and patient-related factors may certainly contribute to the aetiology, surgical technique is also a significant factor in all forms of post-operative instability.

Cite this article: Bone Joint J 2014;96-B(11 Suppl A):112–4.

The role of arthroscopy in the treatment of soft-tissue injuries associated with proximal tibial fractures remains debatable. Our hypothesis was that MRI over-diagnoses clinically relevant associated soft-tissue injuries. This prospective study involved 50 consecutive patients who underwent surgical treatment for a split-depression fracture of the lateral tibial condyle (AO/OTA type B3.1). The mean age of patients was 50 years (23 to 86) and 27 (54%) were female. All patients had MRI and arthroscopy. Arthroscopy identified 12 tears of the lateral meniscus, including eight bucket-handle tears that were sutured and four that were resected, as well as six tears of the medial meniscus, of which five were resected. Lateral meniscal injuries were diagnosed on MRI in four of 12 patients, yielding an overall sensitivity of 33% (95% confidence interval (CI) 11 to 65). Specificity was 76% (95% CI 59 to 88), with nine tears diagnosed among 38 menisci that did not contain a tear. MRI identified medial meniscal injuries in four of six patients, yielding an overall sensitivity of 67% (95% CI 24 to 94). Specificity was 66% (95% CI 50 to 79), with 15 tears diagnosed in 44 menisci that did not contain tears.

MRI appears to offer only a marginal benefit as the specificity and sensitivity for diagnosing meniscal injuries are poor in patients with a fracture. There were fewer arthroscopically-confirmed associated lesions than reported previously in MRI studies.

Cite this article: Bone Joint J 2014;96-B:1631–6.

Primary total knee arthroplasty (TKA) is a reliable procedure with reproducible long-term results. Nevertheless, there are conditions related to the type of patient or local conditions of the knee that can make it a difficult procedure. The most common scenarios that make it difficult are discussed in this review. These include patients with many previous operations and incisions, and those with severe coronal deformities, genu recurvatum, a stiff knee, extra-articular deformities and those who have previously undergone osteotomy around the knee and those with chronic dislocation of the patella.

Each condition is analysed according to the characteristics of the patient, the pre-operative planning and the reported outcomes.

When approaching the difficult primary TKA surgeons should use a systematic approach, which begins with the review of the existing literature for each specific clinical situation.

Cite this article: Bone Joint J 2015;97-B(10 Suppl A):30–9.

The aim of this study was to examine the functional outcome at ten years following lateral closing wedge high tibial osteotomy for medial compartment osteoarthritis of the knee and to define pre-operative predictors of survival and determinants of functional outcome.

164 consecutive patients underwent high tibial osteotomy between 2000 and 2002. A total of 100 patients (100 knees) met the inclusion criteria and 95 were available for review at ten years. Data were collected prospectively and included patient demographics, surgical details, long leg alignment radiographs, Western Ontario and McMaster Universities osteoarthritis index (WOMAC) and Knee Society scores (KSS) pre-operatively and at five and ten years follow-up.

At ten years, 21 patients had been revised at a mean of five years. Overall Kaplan–Meier survival was 87% (95% confidence interval (CI) 81 to 94) and 79% (95% CI 71 to 87) at five and ten years, respectively. When compared with unrevised patients, those who had been revised had significantly lower mean pre-operative WOMAC Scores (47 (21 to 85) vs 65 (32 to 99), p < 0.001), higher mean age (54 yrs (42 to 61) vs 49 yrs (26 to 66), p = 0.006) and a higher mean BMI (30.2; 25 to 39 vs 27.9; 21 to 36, p = 0.005). Each were found to be risk factors for revision, with hazard ratios of 10.7 (95% CI 4 to 28.6; pre-operative WOMAC < 45), 6.5 (95% CI 2.4 to 17.7; age > 55) and 3.0 (95%CI 1.2 to 7.6; BMI > 30). Survival of patients with pre-operative WOMAC > 45, age < 55 and BMI < 30 was 97% at five and ten years. WOMAC and KSS in surviving patients improved significantly between pre-operative (mean 61; 32 to 99) and five (mean 88; 35 to 100, p = 0.001) and ten years (mean 84; 38 to 100, p = 0.001). Older patients had better functional outcomes overall, despite their higher revision rate.

This study has shown that improved survival is associated with age < 55 years, pre-operative WOMAC scores > 45 and, a BMI < 30. In patients over 55 years of age with adequate pre-operative functional scores, survival can be good and functional outcomes can be significantly better than their younger counterparts. We recommend the routine use of pre-operative functional outcome scores to guide decision-making when considering suitability for high tibial osteotomy.

Cite this article: Bone Joint J 2014;96-B:1491–7.

Obesity is an epidemic across both the developed and developing nations that is possibly the most important current public health factor affecting the morbidity and mortality of the global population. Obese patients have the potential to pose several challenges for arthroplasty surgeons from the standpoint of the influence obesity has on osteoarthritic symptoms, their peri-operative medical management, the increased intra-operative technical demands on the surgeon, the intra- and post-operative complications, the long term outcomes of total hip and knee arthroplasty. Also, there is no consensus on the role the arthroplasty surgeon should have in facilitating weight loss for these patients, nor whether obesity should affect the access to arthroplasty procedures.

The August 2012 Trauma Roundup³⁶⁰ looks at: pelvic fractures, thromboembolism and the Japanese; venous thromboembolism risk after pelvic and acetabular fractures; the displaced clavicular fracture; whether to use a nail or plate for the displaced fracture of the distal tibia; the dangers of snowboarding; how to predict the outcome of lower leg blast injuries; compressive external fixation for the displaced patellar fracture; broken hips in Morocco; and spinal trauma in mainland China.

We present the first reported case of symptomatic medial dislocation of the medial meniscus in a patient who had no previous history of trauma and who had an otherwise normal knee. The treatment of instability of the medial meniscus is controversial and studies have indicated that certain individuals without a firm meniscal bony insertion may be predisposed to meniscal dislocation. In our patient, the meniscal instability interfered with daily activities. Operative stabilisation by reconstruction of the meniscotibial ligaments cured the symptoms.

Objectives

This study aimed to investigate time-dependent gene expression of injured human anterior cruciate ligament (ACL), and to evaluate the histological changes of the ACL remnant in terms of cellular characterisation.