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.

There is a disparity in sport-related injuries between sexes, with females sustaining non-contact musculoskeletal injuries at a higher rate. Anterior cruciate ligament ruptures are between two and eight times more common than in males, and females also have a higher incidence of ankle sprains, patellofemoral pain, and bone stress injuries. The sequelae of such injuries can be devastating to an athlete, resulting in time out of sport, surgery, and the early onset of osteoarthritis. It is important to identify the causes of this disparity and introduce prevention programmes to reduce the incidence of these injuries. A natural difference reflects the effect of reproductive hormones in females, which have receptors in certain musculoskeletal tissues. Relaxin increases ligamentous laxity. Oestrogen decreases the synthesis of collagen and progesterone does the opposite. Insufficient diet and intensive training can lead to menstrual irregularities, which are common in female athletes and result in injury, whereas oral contraception may have a protective effect against certain injuries. It is important for coaches, physiotherapists, nutritionists, doctors, and athletes to be aware of these issues and to implement preventive measures. This annotation explores the relationship between the menstrual cycle and orthopaedic sports injuries in pre-menopausal females, and proposes recommendations to mitigate the risk of sustaining these injuries.

Cite this article: Bone Joint J 2023;105-B(7):723–728.

Periprosthetic femoral fractures are increasing in incidence, and typically occur in frail elderly patients. They are similar to pathological fractures in many ways. The aims of treatment are the same, including 'getting it right first time' with a single operation, which allows immediate unrestricted weightbearing, with a low risk of complications, and one that avoids the creation of stress risers locally that may predispose to further peri-implant fracture. The surgical approach to these fractures, the associated soft-tissue handling, and exposure of the fracture are key elements in minimizing the high rate of complications. This annotation describes the approaches to the femur that can be used to facilitate the surgical management of peri- and interprosthetic fractures of the femur at all levels using either modern methods of fixation or revision arthroplasty.

Cite this article: Bone Joint J 2023;105-B(6):593–601.

Anterior cruciate ligament (ACL) graft failure from rupture, attenuation, or malposition may cause recurrent subjective instability and objective laxity, and occurs in 3% to 22% of ACL reconstruction (ACLr) procedures. Revision ACLr is often indicated to restore knee stability, improve knee function, and facilitate return to cutting and pivoting activities. Prior to reconstruction, a thorough clinical and diagnostic evaluation is required to identify factors that may have predisposed an individual to recurrent ACL injury, appreciate concurrent intra-articular pathology, and select the optimal graft for revision reconstruction. Single-stage revision can be successful, although a staged approach may be used when optimal tunnel placement is not possible due to the position and/or widening of previous tunnels. Revision ACLr often involves concomitant procedures such as meniscal/chondral treatment, lateral extra-articular augmentation, and/or osteotomy. Although revision ACLr reliably restores knee stability and function, clinical outcomes and reoperation rates are worse than for primary ACLr.

Cite this article: Bone Joint J 2023;105-B(5):474–480.

Recent publications have drawn attention to the fact that some brands of joint replacement may contain variants which perform significantly worse (or better) than their ‘siblings’. As a result, the National Joint Registry has performed much more detailed analysis on the larger families of knee arthroplasties in order to identify exactly where these differences may be present and may hitherto have remained hidden. The analysis of the Nexgen knee arthroplasty brand identified that some posterior-stabilized combinations have particularly high revision rates for aseptic loosening of the tibia, and consequently a medical device recall has been issued for the Nexgen ‘option’ tibial component which was implicated. More elaborate signal detection is required in order to identify such variation in results in a routine fashion if patients are to be protected from such variation in outcomes between closely related implant types.

Cite this article: Bone Joint J 2023;105-B(3):221–226.

Orthopaedic surgeons are currently faced with an overwhelming number of choices surrounding total knee arthroplasty (TKA), not only with the latest technologies and prostheses, but also fundamental decisions on alignment philosophies. From ‘mechanical’ to ‘adjusted mechanical’ to ‘restricted kinematic’ to ‘unrestricted kinematic’ — and how constitutional alignment relates to these — there is potential for ambiguity when thinking about and discussing such concepts. This annotation summarizes the various alignment strategies currently employed in TKA. It provides a clear framework and consistent language that will assist surgeons to compare confidently and contrast the concepts, while also discussing the latest opinions about alignment in TKA. Finally, it provides suggestions for applying consistent nomenclature to future research, especially as we explore the implications of 3D alignment patterns on patient outcomes.

Cite this article: Bone Joint J 2023;105-B(2):102–108.

Paediatric bone sarcomas are a dual challenge for orthopaedic surgeons in terms of tumour resection and reconstruction, as it is important to minimize functional and growth problems without compromising survival rates. Cañadell’s technique consists of a Type I epiphysiolysis performed using continuous distraction by an external fixator prior to resection. It was designed to achieve a safe margin due to the ability of the physeal cartilage to be a barrier to tumour spread in some situations, avoiding the need for articular reconstruction, and preserving the growth capacity most of the times. Despite initial doubts raised in the scientific community, this technique is now widely used in many countries for the treatment of metaphyseal paediatric bone sarcomas. This annotation highlights the importance of Cañadell’s work and reviews the experience of applying it to bone sarcoma patients over the last 40 years.

Cite this article: Bone Joint J 2023;105-B(1):11–16.

We aim to explore the potential technologies for monitoring and assessment of patients undergoing arthroplasty by examining selected literature focusing on the technology currently available and reflecting on possible future development and application. The reviewed literature indicates a large variety of different hardware and software, widely available and used in a limited manner, to assess patients’ performance. There are extensive opportunities to enhance and integrate the systems which are already in existence to develop patient-specific pathways for rehabilitation.

Cite this article: Bone Joint J 2022;104-B(10):1104–1109.

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.

Stable fractures of the ankle can be safely treated non-operatively. It is also gradually being recognised that the integrity of the ‘medial column’ is essential for the stability of the fracture. It is generally thought that bi- and tri-malleolar fractures are unstable, as are pronation external rotation injuries resulting in an isolated high fibular fracture (Weber type-C), where the deltoid ligament is damaged or the medial malleolus fractured. However, how best to identify unstable, isolated, trans-syndesmotic Weber type-B supination external rotation (SER) fractures of the lateral malleolus remains controversial.

We provide a rationale as to how to classify SER distal fibular fractures using weight-bearing radiographs, and how this can help guide the management of these common injuries.

Cite this article: Bone Joint J 2017;99-B:851–5.

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.

There are three basic concepts that are important to the biomechanics of pedicle screw-based instrumentation. First, the outer diameter of the screw determines pullout strength, while the inner diameter determines fatigue strength. Secondly, when inserting a pedicle screw, the dorsal cortex of the spine should not be violated and the screws on each side should converge and be of good length. Thirdly, fixation can be augmented in cases of severe osteoporosis or revision.

A trajectory parallel or caudal to the superior endplate can minimise breakage of the screw from repeated axial loading. Straight insertion of the pedicle screw in the mid-sagittal plane provides the strongest stability.

Rotational stability can be improved by adding transverse connectors. The indications for their use include anterior column instability, and the correction of rotational deformity.

The aim of this study was to determine whether the foundation programme for junior doctors, implemented across the United Kingdom in 2005, provides adequate training in musculoskeletal medicine. We recruited 112 doctors on completion of their foundation programme and assessed them using the Freedman and Bernstein musculoskeletal examination tool. Only 8.9% passed the assessment. Those with exposure to orthopaedics, with a career interest in orthopaedics, and who felt that they had gained adequate exposure to musculoskeletal medicine obtained significantly higher scores. Those interested in general practice as a career obtained significantly lower scores. Only 15% had any exposure to orthopaedics during the foundation programme and only 13% felt they had adequate exposure to musculoskeletal medicine. The foundation programme currently provides inadequate training in musculoskeletal medicine. The quality and quantity of exposure to musculoskeletal medicine during the foundation programme must be improved.

This annotation discusses the findings of two papers in the current issue describing the management of the neurovascular complications of supracondylar fractures of the humerus in childhood, with particular reference to the indications for and the timing of exploration of the brachial artery and the affected nerves.

Advances in hip arthroscopy have renewed interest in the ligamentum teres. Considered by many to be a developmental vestige, it is now recognised as a significant potential source of pain and mechanical symptoms arising from the hip joint. Despite improvements in imaging, arthroscopy remains the optimum method of diagnosing lesions of the ligamentum teres. Several biological or mechanical roles have been proposed for the ligament. Unless these are disproved, the use of surgical procedures that sacrifice the ligamentum teres, as in surgical dislocation of the hip, should be carefully considered. This paper provides an update on the development, structure and function of the ligamentum teres, and discusses associated clinical implications.

The Jaipur foot was developed for barefoot amputees by Professor P. K. Sethi. He used local artisans and readily available materials. The prosthesis was cheap and could be made in one hour. It enabled amputees to work in rural conditions, muddy and wet fields and to climb trees. It has been widely used in India, South East Asia and Africa, where local variations to the design have now been made.

There is a trend towards the use of double-bundle techniques for the reconstruction of the anterior cruciate ligament. This has not been substantiated scientifically. The functional outcome of these techniques is equivalent to that of single-bundle methods. The main advantage of a double-bundle rather than a single-bundle reconstruction should be a better rotational stability, but the validity and accuracy of systems for the measurement of rotational stability have not been confirmed.

Despite the enthusiasm of surgeons for the double-bundle technique, reconstruction with a single-bundle should remain the standard method for managing deficiency of the anterior cruciate ligament until strong evidence in favour of the use of the double-bundle method is available.

In an adult man the mean femoral anteversion angle measures approximately 15°, for which the reasons have never been fully elucidated. An assortment of simian and quadruped mammalian femora was therefore examined and the anteversion angles measured. A simple static mathematical model was then produced to explain the forces acting on the neck of the femur in the quadruped and in man. Femoral anteversion was present in all the simian and quadruped femora and ranged between 4° and 41°. It thus appears that man has retained this feature despite evolving from quadrupedal locomotion. Quadrupeds generally mobilise with their hips flexed forwards from the vertical; in this position, it is clear that anteversion gives biomechanical advantage against predominantly vertical forces. In man with mobilisation on vertical femora, the biomechanical advantage of anteversion is against forces acting mainly in the horizontal plane. This has implications in regard to the orientation of hip replacements