One hundred and fifty asymptomatic shoulders in 75 schoolchildren were studied. The shoulders were tested for instability and a hyperextensometer was used to assess joint laxity. Signs of instability were found in 57% of the shoulders in boys and 48% in girls; the commonest sign was a positive posterior drawer test which was found in 63 shoulders. A positive sulcus sign was found in 17 shoulders and 17 subjects had signs of multidirectional instability. General joint laxity was not a feature of subjects whose shoulders had positive instability signs

Using roentgen stereophotogrammetry we have recorded the three-dimensional movements of the knee during an anteroposterior laxity test in 36 patients with torn anterior cruciate ligaments and in three cadaver knees. At 30 degrees of knee flexion and before loads were applied the tibia occupied a more laterally rotated position if the anterior cruciate ligament had been injured. When the tibia was pulled anteriorly knees with cruciate deficiency rotated more laterally and were more abducted than normal knees. Posterior traction induced lateral rotation in the injured knee and medial rotation in the intact one. Precise knowledge of the three-dimensional instability of the anterior cruciate deficient knee may be important when the laxity is evaluated only in relation to one of the three cardinal axes

In a prospective study, 41 consecutive patients with a partial tear of the anterior cruciate ligament, diagnosed by arthroscopy, were reviewed after an average of 17 months, having been in plaster for six weeks after injury. Their average age was 29 years and review included clinical examination, measurement of anterior and posterior laxity with the Stryker knee laxity tester as well as evaluation of knee function and activity level. Twenty-one patients had unstable knees at follow-up; the mean total anteroposterior laxity for these patients was 12.6 +/- 3.9 mm compared with 7.1 +/- 4.3 mm for the normal knee. Most patients had few symptoms, but there was a significant reduction in the mean level of activity in the unstable group

1. Recurrence of deformity after operations for drop foot is often associated with opening of the front of the ankle joint: this has previously been regarded as a complication of the operation. 2. This study of sixty paralytic drop feet treated conservatively reveals that this laxity was in fact present in no less than 43 per cent. 3. The laxity is most commonly found when the calf muscle is strong and it can occur within a year of the onset of the paralysis. It is not always prevented by wearing a toe-raising spring. 4. Such anterior laxity may well be a common cause of failure of many of the standard operations for drop foot. 5. Before operation for drop foot is undertaken a lateral radiograph of the ankle should be taken in forced plantar-flexiori. If this demonstrates anterior laxity any standard operation is unlikely to succeed unless the anterior fibres of the collateral ligaments are protected from strain by simultaneous tendon transplantation or unless the ankle is included in the arthrodesis

Aims

In the native hip, the hip capsular ligaments tighten at the limits of range of hip motion and may provide a passive stabilizing force to protect the hip against edge loading. In this study we quantified the stabilizing force vectors generated by capsular ligaments at extreme range of motion (ROM), and examined their ability to prevent edge loading.

Aims

Neither a surgeon’s intraoperative impression nor the parameters of computer navigation have been shown to be predictive of the outcomes following total knee arthroplasty (TKA). The aim of this study was to determine whether a surgeon, with robotic assistance, can predict the outcome as assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain (KPS), one year postoperatively, and establish what factors correlate with poor KOOS scores in a well-aligned and balanced TKA.

We have developed an apparatus to measure the anteroposterior stability of the knee to forces of up to 250 N, applied at 20 degrees of flexion. We measured anterior laxity at 200 N, anterior stiffness at 50 N and total laxity at +/- 200 N. A study of cadaveric knees revealed that the soft tissues surrounding the bones had a significant influence on the force-displacement curve, and emphasised that differences between injured and normal pairs of knees are much more important than the absolute values of the parameters. In 61 normal volunteers we found no significant left to right differences in anterior laxity at 200 N and anterior stiffness at 50 N. In 92 patients with unilateral anterior cruciate deficiency there were significant differences (p less than 0.0005) in anterior laxity, anterior stiffness and total laxity, the injured-normal differences averaging 6.7 mm, 1.3 N/mm, and 8.1 mm respectively

We have undertaken a randomized clinical trial comparing two methods of reconstruction of the anterior cruciate ligament in patients with chronic instability. We used an ipsilateral bone-patellar-tendon-bone autograft in 27 patients and the Ligament Advancement Reinforcement System (LARS) artificial ligament in 26. Assessment before and at two, six, 12 and 24 months after surgery, included the history, physical examination, a modified International Knee Documentation Committee (IKDC) score, the Tegner score, the Knee Injury and Osteoarthritis Outcome Score (KOOS) and instrumented laxity testing. There were no cases of reactive synovitis or of infection of the knee, and there was no difference regarding the failure rate between the two groups. The IKDC showed no significant differences between the two groups at any stage of the follow-up. The KOOS evaluation showed consistently better results in all subscales for the LARS group during the first year of follow-up. After 24 months these differences were no longer evident. Instrument-tested laxity was greater in the LARS group at all stages of follow-up, but the differences were not significant at 24 months. Our findings suggest that at follow-up at 24 months the LARS ligament seems to be a satisfactory treatment option, especially when an early return to high levels of activity is demanded

Aims

The effect of pelvic tilt (PT) and sagittal balance in hips with pincer-type femoroacetabular impingement (FAI) with acetabular retroversion (AR) is controversial. It is unclear if patients with AR have a rotational abnormality of the iliac wing. Therefore, we asked: are parameters for sagittal balance, and is rotation of the iliac wing, different in patients with AR compared to a control group?; and is there a correlation between iliac rotation and acetabular version?

Aims

Medial pivot (MP) total knee arthroplasties (TKAs) were designed to mimic native knee kinematics with their deep medial congruent fitting of the tibia to the femur almost like a ball-on-socket, and a flat lateral part. GMK Sphere is a novel MP implant. Our primary aim was to study the migration pattern of the tibial tray of this TKA.

Aims

The removal of the cruciate ligaments in total knee arthroplasty (TKA) has been suggested as a potential contributing factor to patient dissatisfaction, due to alteration of the in vivo biomechanics of the knee. Bicruciate retaining (BCR) TKA allows the preservation of the cruciate ligaments, thus offering the potential to reproduce healthy kinematics. The aim of this study was to compare in vivo kinematics between the operated and contralateral knee in patients who have undergone TKA with a contemporary BCR design.

Aims

Ideal component sizing may be difficult to achieve in unicompartmental knee arthroplasty (UKA). Anatomical variants, incremental implant size, and a reduced surgical exposure may lead to over- or under-sizing of the components. The purpose of this study was to compare the accuracy of UKA sizing with robotic-assisted techniques versus a conventional surgical technique.

Dysplasia of the hip, hypotonia, osteopenia, ligamentous laxity, and mental retardation increase the complexity of performing and managing patients with Down syndrome who require total hip replacement (THR). We identified 14 patients (six males, eight females, 21 hips) with Down syndrome and degenerative disease of the hip who underwent THR, with a minimum follow-up of two years from 1969 to 2009. In seven patients, bilateral THRs were performed while the rest had unilateral THRs. The mean clinical follow-up was 5.8 years (standard deviation (. sd. ) 4.7; 2 to 17). The mean Harris hip score was 37.9 points (. sd. 7.8) pre-operatively and increased to 89.2 (. sd. 12.3) at final follow-up (p = 1x10. -9. ). No patient suffered a post-operative dislocation. In three patients, four hips had revision THR for aseptic loosening at a mean follow-up of 7.7 years (. sd. 6.3; 3 to 17). This rate of revision THR was higher than expected. Our patients with Down syndrome benefitted clinically from THR at mid-term follow-up. Cite this article: Bone Joint J 2014;96-B:1455–8

Cite this article: Bone Joint Open 2020;1-11:706–708.

Aims

To report mid- to long-term results of Oxford mobile bearing domed lateral unicompartmental knee arthroplasty (UKA), and determine the effect of potential contraindications on outcome.

Aims

This study aims to investigate the effects of posterior tibial slope (PTS) on knee kinematics involved in the post-cam mechanism in bi-cruciate stabilized (BCS) total knee arthroplasty (TKA) using computer simulation.