Aims

Osteoarthritis (OA) is the most prevalent systemic musculoskeletal disorder, characterized by articular cartilage degeneration and subchondral bone (SCB) sclerosis. Here, we sought to examine the contribution of accelerated growth to OA development using a murine model of excessive longitudinal growth. Suppressor of cytokine signalling 2 (SOCS2) is a negative regulator of growth hormone (GH) signalling, thus mice deficient in SOCS2 (Socs2^-/-) display accelerated bone growth.

Aims

Femoral bone preparation using compaction technique has been shown to preserve bone and improve implant fixation in animal models. No long-term clinical outcomes are available. There are no significant long-term differences between compaction and broaching techniques for primary total hip arthroplasty (THA) in terms of migration, clinical, and radiological outcomes.

Our goal was to evaluate the use of Ponseti’s method, with minor adaptations, in the treatment of idiopathic clubfeet presenting in children between five and ten years of age. A retrospective review was performed in 36 children (55 feet) with a mean age of 7.4 years (5 to 10), supplemented by digital images and video recordings of gait. There were 19 males and 17 females. The mean follow-up was 31.5 months (24 to 40). The mean number of casts was 9.5 (6 to 11), and all children required surgery, including a percutaneous tenotomy or open tendo Achillis lengthening (49%), posterior release (34.5%), posterior medial soft-tissue release (14.5%), or soft-tissue release combined with an osteotomy (2%). The mean dorsiflexion of the ankle was 9° (0° to 15°). Forefoot alignment was neutral in 28 feet (51%) or adducted (< 10°) in 20 feet (36%), > 10° in seven feet (13%). Hindfoot alignment was neutral or mild valgus in 26 feet (47%), mild varus (< 10°) in 19 feet (35%), and varus (> 10°) in ten feet (18%). Heel–toe gait was present in 38 feet (86%), and 12 (28%) exhibited weight-bearing on the lateral border (out of a total of 44 feet with gait videos available for analysis). Overt relapse was identified in nine feet (16%, six children). The parents of 27 children (75%) were completely satisfied. A plantigrade foot was achieved in 46 feet (84%) without an extensive soft-tissue release or bony procedure, although under-correction was common, and longer-term follow-up will be required to assess the outcome. Cite this article: Bone Joint J 2013;95-B:1721–5

We conducted a retrospective study to investigate the effect of femoral bowing on the placement of components in total knee replacement (TKR), with regard to its effect on reestablishing the correct mechanical axis, as we hypothesised that computer-assisted total knee replacement (CAS-TKR) would produce more accurate alignment than conventional TKR. Between January 2006 and December 2009, 212 patients (306 knees) underwent TKR. The conventional TKR was compared with CAS-TKR for accuracy of placement of the components and post-operative alignment, as determined by five radiological measurements. There were significant differences in the reconstructed mechanical axes between the bowed and the non-bowed group after conventional TKR (176.2° (. sd. 3.4) vs 179.3° (. sd. 2.1), p < 0.001). For patients with significant femoral bowing, the reconstructed mechanical axes were significantly closer to normal in the CAS group than in the conventional group (179.2° (. sd. 1.9) vs 176.2° (. sd. 3.4), p < 0.001). Femoral bowing resulted in inaccuracy when a conventional technique was used. CAS-TKR provides an effective method of restoring the mechanical axis in the presence of significant femoral bowing

Aims

The aim of this study was to compare the clinical outcomes of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) during the first six weeks and at one year postoperatively.

A total of 20 pairs of fresh-frozen cadaver femurs were assigned to four alignment groups consisting of relative varus (10° and 20°) and relative valgus (10° and 20°), 75 composite femurs of two neck geometries were also used. In both the cadaver and the composite femurs, placing the component in 20° of valgus resulted in a significant increase in load to failure. Placing the component in 10° of valgus had no appreciable effect on increasing the load to failure except in the composite femurs with varus native femoral necks. Specimens in 10° of varus were significantly weaker than the neutrally-aligned specimens. The results suggest that retention of the intact proximal femoral strength occurs at an implant angulation of ≥ 142°. However, the benefit of extreme valgus alignment may be outweighed in clinical practice by the risk of superior femoral neck notching, which was avoided in this study

After obtaining informed consent, 80 patients were randomised to undergo a navigated or conventional total knee replacement. All received a cemented, unconstrained, cruciate-retaining implant with a rotating platform. Full-length standing and lateral radiographs and CT scans of the hip, knee and ankle joint were carried out five to seven days after operation. No notable differences were found between computer-assisted navigation and conventional implantation techniques as regards the rotational alignment of the femoral or tibial components. Although the deviation from the transepicondylar axis was relatively low, there was a considerable range of deviation for the tibial rotational alignment. There was no statistically significant difference regarding the occurrence pattern of outliers in mechanical malalignment but the number of outliers was reduced in the navigated group

The December 2015 Knee Roundup360 looks at: Albumin and complications in knee arthroplasty; Tantalum: a knee fixation for all seasons?; Dynamic knee alignment; Tibial component design in UKA; Managing the tidal wave of revision knee arthroplasty; Scoring pain in TKR; Does anyone have a ‘normal’ tibial slope?; XLPE in TKR? A five-year clinical study; Spacers and infected revision arthroplasties; Dialysis and arthroplasty

Objectives. The objective of this study was to assess the association between whole body sagittal balance and risk of falls in elderly patients who have sought treatment for back pain. Balanced spinal sagittal alignment is known to be important for the prevention of falls. However, spinal sagittal imbalance can be markedly compensated by the lower extremities, and whole body sagittal balance including the lower extremities should be assessed to evaluate actual imbalances related to falls. Methods. Patients over 70 years old who visited an outpatient clinic for back pain treatment and underwent a standing whole-body radiograph were enrolled. Falls were prospectively assessed for 12 months using a monthly fall diary, and patients were divided into fallers and non-fallers according to the history of falls. Radiological parameters from whole-body radiographs and clinical data were compared between the two groups. Results. A total of 144 patients (120 female patients and 24 male patients) completed a 12-month follow-up for assessing falls. A total of 31 patients (21.5%) reported at least one fall within the 12-month follow-up. In univariate logistic regression analysis, the risk of falls was significantly increased in older patients and those with more medical comorbidities, decreased lumbar lordosis, increased sagittal vertical axis, and increased horizontal distance between the C7 plumb line and the centre of the ankle (C7A). Increased C7A was significantly associated with increased risk of falls even after multivariate adjustment. Conclusion. Whole body sagittal balance, measured by the horizontal distance between the C7 plumb line and the centre of the ankle, was significantly associated with risk of falls among elderly patients with back pain. Cite this article: J. Kim, J. Y. Hwang, J. K. Oh, M. S. Park, S. W. Kim, H. Chang, T-H. Kim. The association between whole body sagittal balance and risk of falls among elderly patients seeking treatment for back pain. Bone Joint Res 2017;6:–344. DOI: 10.1302/2046-3758.65.BJR-2016-0271.R2

Objectives. Little biomechanical information is available about kinematically aligned (KA) total knee arthroplasty (TKA). The purpose of this study was to simulate the kinematics and kinetics after KA TKA and mechanically aligned (MA) TKA with four different limb alignments. Materials and Methods. Bone models were constructed from one volunteer (normal) and three patients with three different knee deformities (slight, moderate and severe varus). A dynamic musculoskeletal modelling system was used to analyse the kinematics and the tibiofemoral contact force. The contact stress on the tibial insert, and the stress to the resection surface and medial tibial cortex were examined by using finite element analysis. Results. In all bone models, posterior translation on the lateral side and external rotation in the KA TKA models were greater than in the MA TKA models. The tibiofemoral force at the medial side was increased in the moderate and severe varus models with KA TKA. In the severe varus model with KA TKA, the contact stress on the tibial insert and the stress to the resection surface and to the medial tibial cortex were increased by 41.5%, 32.2% and 53.7%, respectively, compared with MA TKA, and the bone strain at the medial side was highest among all models. Conclusion. Near normal kinematics was observed in KA TKA. However, KA TKA increased the contact force, stress and bone strain at the medial side for moderate and severe varus knee models. The application of KA TKA for severe varus knees may be inadequate. Cite this article: S. Nakamura, Y. Tian, Y. Tanaka, S. Kuriyama, H. Ito, M. Furu, S. Matsuda. The effects of kinematically aligned total knee arthroplasty on stress at the medial tibia: A case study for varus knee. Bone Joint Res 2017;6:43–51. DOI: 10.1302/2046-3758.61.BJR-2016-0090.R1

Aims

Total hip arthroplasties (THAs) are performed by surgeons at various stages in training with varying levels of supervision, but we do not know if this is safe practice with comparable outcomes to consultant-performed THA. Our aim was to examine the association between surgeon grade, the senior supervision of trainees, and the risk of revision following THA.

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The cemented Oxford unicompartmental knee arthroplasty (OUKA) features two variants: single and twin peg OUKA. The purpose of this study was to assess the stability of both variants in a worst-case scenario of bone defects and suboptimal cementation.

Aims

Osteofibrous dysplasia (OFD) is a rare benign lesion predominantly affecting the tibia in children. Its potential link to adamantinoma has influenced management. This international case series reviews the presentation of OFD and management approaches to improve our understanding of OFD.

Aims

The aims of this study were to investigate the ability to kneel after total knee arthroplasty (TKA) without patellar resurfacing, and its effect on patient-reported outcome measures (PROMs). Secondary aims included identifying which kneeling positions were most important to patients, and the influence of radiological parameters on the ability to kneel before and after TKA.

The development of spinal deformity in children with underlying neurodisability can affect their ability to function and impact on their quality of life, as well as compromise provision of nursing care. Patients with neuromuscular spinal deformity are among the most challenging due to the number and complexity of medical comorbidities that increase the risk for severe intraoperative or postoperative complications. A multidisciplinary approach is mandatory at every stage to ensure that all nonoperative measures have been applied, and that the treatment goals have been clearly defined and agreed with the family. This will involve input from multiple specialities, including allied healthcare professionals, such as physiotherapists and wheelchair services. Surgery should be considered when there is significant impact on the patients’ quality of life, which is usually due to poor sitting balance, back or costo-pelvic pain, respiratory complications, or problems with self-care and feeding. Meticulous preoperative assessment is required, along with careful consideration of the nature of the deformity and the problems that it is causing. Surgery can achieve good curve correction and results in high levels of satisfaction from the patients and their caregivers. Modern modular posterior instrumentation systems allow an effective deformity correction. However, the risks of surgery remain high, and involvement of the family at all stages of decision-making is required in order to balance the risks and anticipated gains of the procedure, and to select those patients who can mostly benefit from spinal correction.

We report the outcome of 32 patients (37 knees) who underwent hemicallostasis with a dynamic external fixator for osteoarthritis of the medial compartment of the knee. There were 16 men (19 knees) and 16 women (18 knees) with a mean age at operation of 54.6 years (27 to 72). The aim was to achieve a valgus overcorrection of 2° to 8° or mechanical axis at 62.5% (± 12.5%). At a mean follow-up of 62.8 months (51 to 81) there was no change in the mean range of movement, and no statistically significant difference in the Insall-Salvati index or tibial slope (p = 0.11 and p = 0.15, respectively). The mean hip-knee-ankle angle changed from 190.6 (183° to 197°) to 176.0° (171° to 181°), with a mean final position of the mechanical axis of 58.5% (35.1% to 71.2%). The desired alignment was attained in 31 of 37 (84%) knees. There were 21 excellent, 13 good, two fair and one poor result according to the Oxford knee score with no correlation between age and final score. This score was at its best at one year with a statistically significant deterioration at two years (p = 0.001) followed by a small but not statistically significant deterioration until the final follow-up (p = 0.17). All the knees with Ahlback grade 1 osteoarthritis had excellent or good results. Complications included pin tract infections involving 16.4% of all pins used, delayed union in two, knee stiffness in four, fracture of the lateral cortex in one and ring sequestrum in one. In conclusion, hemicallostasis provides precision in attaining the desired alignment without interfering with tibial slope or patellar height, and is relatively free of serious complications

We have investigated the accuracy of placement of the femoral component using imageless navigation in 100 consecutive Birmingham Hip Resurfacings. Pre-operative templating determined the native neck-shaft angle and planned stem-shaft angle of the implant. The latter were verified post-operatively using digital anteroposterior unilateral radiographs of the hip. The mean neck-shaft angle determined before operation was 132.7° (118° to 160°). The mean planned stem-shaft angle was a relative valgus alignment of 9.7° (. sd. 2.6). The stem-shaft angle after operation differed from that planned by a mean of 2.8° (. sd. 2.0) and in 86% of cases the final angle measured within ± 5° of that planned. We had no instances of notching of the neck or varus alignment of the implant in our series. A learning curve was observed in the time taken for navigation, but not for accurate placement of the implant. Navigation in hip resurfacing may afford the surgeon a reliable and accurate method of placement of the femoral component

Aims

Although the short stem concept in hip arthroplasty procedure shows acceptable clinical performance, we sometimes get unexplainable radiological findings. The aim of this retrospective study was to evaluate changes of radiological findings up to three years postoperatively, and to assess any potential contributing factors on such radiological change in a Japanese population.