Personalised 3D Printed high tibial osteotomy achieves a high level of accuracy: 'IDEAL' preclinical stage evaluation of a novel patient specific system.

High tibial osteotomy (HTO) is an effective surgical treatment for isolated medial compartment knee osteoarthritis; however, widespread adoption is limited due to difficulty in achieving the planned correction, and patient dissatisfaction due to soft tissue irritation. The aim of this study was to assess the accuracy of a novel HTO system with 3D printed patient specific implants and surgical guides using cadaveric specimens. Local ethics committee approval was obtained. The novel opening wedge HTO procedure was performed on eight cadaver leg specimens. Whole lower limb CT scans pre- and post-operatively provided geometrical assessment quantifying the discrepancy between pre-planned and post-operative measurements for key variables: the gap opening angle and the patient specific surgical instrumentation positioning. The average discrepancy between the pre-operative plan and the post-operative osteotomy correction angle was: 0.0 ±â€ˆ0.2° The R2 value for the regression correlation was 0.95. The average error in implant positioning was -0.4 ±â€ˆ4.3 mm, -2.6 ±â€ˆ3.4 mm and 3.1 ±â€ˆ1.7° vertically, horizontally, and rotationally respectively. This novel HTO surgery has greater accuracy in correction angle achieved compared to that reported for conventional or other patient specific methods with published data available. This system could potentially improve the accuracy of osteotomy correction angles achieved surgically.

The largest survivorship and clinical outcomes study of the fixed bearing Stryker Triathlon Partial Knee Replacement - A multi-surgeon, single centre cohort study with a minimum of two years of follow-up.

BACKGROUND: The surgical management of isolated medial compartment degenerative disease of the knee causes debate. Unicompartmental arthroplasty options include fixed and mobile bearing implant designs with fixed bearing becoming increasingly popular. We present the largest cohort of a fixed bearing single radius design, Stryker Triathlon Partial Knee Replacement (PKR). METHODS: We prospectively collected demographic data and patient reported outcome measures (PROMs) on our cohort of PKR implants since its adoption in our unit, 2009 until March 2015. RESULTS: A total of 129 implants in 115 patients with a mean follow-up of 5.5 years (2.5 to 8.5 years) were included. There were 11 revisions at an average of 1.7 years (0.6-4.1 years), two for infection, two for mal-alignment, five for progression of disease and two for loosening. The survivorship of the implants at five years is 90%. CONCLUSION: The PKR provides good survivorship at five years and PROM scores that are equal to the largest and most popular comparable implants. There is an associated learning curve with this implant, as there is with all systems and this is reflected in our results.

Mid-term survivorship and clinical outcomes of the Avon patellofemoral joint replacement.

BACKGROUND: We present the largest series of Avon patellofemoral joint (PFJ) replacements outside of the design centre. There is discussion over its efficacy and usefulness. We report an independent opinion of its indications, survivorship and outcomes. METHODS: We prospectively collected demographic data and patient reported outcome measures (PROM's) on our cohort of Avon Patellofemoral replacements since its adoption in our unit in 2003 until 2014. We performed a retrospective review of radiographs. RESULTS: We performed 103 PFJ replacements in 85 patients, 36 were male (mean age 61 - range 34 to 78) and 67 female (mean age 60 - range 38 to 82), mean follow up time was 5.6years (range 2.9 to 14.2years) with 93 implants still in situ. Their mean post-operative Oxford Knee Score was 36 (range seven to 48). There were nine conversions to TKR for disease progression and one revision of a femoral component for trochlear malpositioning. Mean time to revision was 2.9years (1.0 to 6.0years). Radiographic evidence of progression on Kellgren and Lawrence score in the un-replaced compartments was demonstrated in 23% of cases with imaging available. The Avon PFJ replacement delivers reproducible and effective pain relief and function to patients with isolated patellofemoral osteoarthritis. We believe PFJ replacement has an important role to play, and we will continue to perform this procedure for a carefully selected group of patients. Conversion to TKR does not and should not be regarded as failure of the index operation.

Adolescent patellar instability: current concepts review.

Patellar instability most frequently presents during adolescence. Congenital and infantile dislocation of the patella is a distinct entity from adolescent instability and measurable abnormalities may be present at birth. In the normal patellofemoral joint an increase in quadriceps angle and patellar height are matched by an increase in trochlear depth as the joint matures. Adolescent instability may herald a lifelong condition leading to chronic disability and arthritis. Restoring normal anatomy by trochleoplasty, tibial tubercle transfer or medial patellofemoral ligament (MPFL) reconstruction in the young adult prevents further instability. Although these techniques are proven in the young adult, they may cause growth arrest and deformity where the physis is open. A vigorous non-operative strategy may permit delay of surgery until growth is complete. Where non-operative treatment has failed a modified MPFL reconstruction may be performed to maintain stability until physeal closure permits anatomical reconstruction. If significant growth remains an extraosseous reconstruction of the MPFL may impart the lowest risk to the physis. If minor growth remains image intensifier guided placement of femoral intraosseous fixation may impart a small, but acceptable, risk to the physis. This paper presents and discusses the literature relating to adolescent instability and provides a framework for management of these patients. Cite this article: Bone Joint J 2017;99-B:159-70.

The early outcome of kinematic versus mechanical alignment in total knee arthroplasty: a prospective randomised control trial.

AIMS: Our aim was to compare kinematic with mechanical alignment in total knee arthroplasty (TKA). PATIENTS AND METHODS: We performed a prospective blinded randomised controlled trial to compare the functional outcome of patients undergoing TKA in mechanical alignment (MA) with those in kinematic alignment (KA). A total of 71 patients undergoing TKA were randomised to either kinematic (n = 36) or mechanical alignment (n = 35). Pre- and post-operative hip-knee-ankle radiographs were analysed. The knee injury and osteoarthritis outcome score (KOOS), American Knee Society Score, Short Form-36, Euro-Qol (EQ-5D), range of movement (ROM), two minute walk, and timed up and go tests were assessed pre-operatively and at six weeks, three and six months and one year post-operatively. RESULTS: A total of 78% of the kinematically aligned group (28 patients) and 77% of the mechanically aligned group (27 patients) were within 3° of their pre-operative plan. There were no statistically significant differences in the mean KOOS (difference 1.3, 95% confidence interval (CI) -9.4 to 12.1, p = 0.80), EQ-5D (difference 0.8, 95% CI -7.9 to 9.6, p = 0.84), ROM (difference 0.1, 95% CI -6.0 to 6.1, p = 0.99), two minute distance tolerance (difference 20.0, 95% CI -52.8 to 92.8, p = 0.58), or timed up and go (difference 0.78, 95% CI -2.3 to 3.9, p = 0.62) between the groups at one year. CONCLUSION: Kinematically aligned TKAs appear to have comparable short-term results to mechanically aligned TKAs with no significant differences in function one year post-operatively. Further research is required to see if any theoretical long-term functional benefits of kinematic alignment are realised or if there are any potential effects on implant survival. Cite this article: Bone Joint J 2016;98-B:1360-8.

The Lateral Meniscus as a Guide to Anatomical Tibial Tunnel Placement During Anterior Cruciate Ligament Reconstruction.

PURPOSE: The aim of the study is to show, on an MRI scan, that the posterior border of the anterior horn of the lateral meniscus (AHLM) could guide tibial tunnel position in the sagittal plane and provide anatomical graft position. METHOD: One hundred MRI scans were analysed with normal cruciate ligaments and no evidence of meniscal injury. We measured the distance between the posterior border of the AHLM and the midpoint of the ACL by superimposing sagittal images. RESULTS: The mean distance between the posterior border of the AHLM and the ACL midpoint was -0.1mm (i.e. 0.1mm posterior to the ACL midpoint). The range was 5mm to -4.6mm. The median value was 0.0mm. 95% confidence interval was from -0.5 to 0.3mm. A normal, parametric distribution was observed and Intra- and inter-observer variability showed significant correlation (p<0.05) using Pearsons Correlation test (intra-observer) and Interclass correlation (inter-observer). CONCLUSION: Using the posterior border of the AHLM is a reproducible and anatomical marker for the midpoint of the ACL footprint in the majority of cases. It can be used intra-operatively as a guide for tibial tunnel insertion and graft placement allowing anatomical reconstruction. There will inevitably be some anatomical variation. Pre-operative MRI assessment of the relationship between AHLM and ACL footprint is advised to improve surgical planning. LEVEL OF EVIDENCE: Level 4.

The outcome of all-inside meniscal repair with relation to previous anterior cruciate ligament reconstruction.

BACKGROUND: Arthroscopically assisted all-inside meniscal repair has become a popular treatment for meniscal tears. Previous studies have suggested a beneficial effect of concomitant anterior cruciate ligament reconstruction on meniscal repair outcomes. The effect of prior cruciate ligament reconstruction (predating the meniscal injury) on meniscal repair success is unreported. The aim of this study was to assess the success of meniscal repair in our practice. Further aims were to analyze the effect of concomitant- and past-anterior cruciate ligament reconstruction on meniscal repair outcomes. METHODS: Retrospective review of all patients undergoing arthroscopic meniscal repair during a 53 month period was performed. Mean followup was 13.5 months (mean 6-50). The primary outcome measure was meniscal reoperation. RESULTS: Sixteen of 104 patients required reoperation, giving an overall meniscal repair success rate of 85%. Patients undergoing concomitant anterior cruciate ligament reconstruction enjoyed significantly improved outcomes (91%, p=0.049), while those with a past history of anterior cruciate ligament reconstruction had significantly worse meniscal repair success rates (63%, p=0.016). CONCLUSIONS: Arthroscopic meniscal repair in a selected patient group offers good success rates, especially when performed with concomitant anterior cruciate ligament reconstruction. We have identified a subgroup of patients, those with a past history of anterior cruciate ligament reconstruction predating the meniscal injury, who appear to have relatively poor outcomes from meniscal repair. Potential reasons for this finding are discussed. LEVEL OF EVIDENCE: Level IV, case series.

Reliability of radiographic measurements of knee motion following knee arthroplasty for use in a virtual knee clinic.

INTRODUCTION: We sought to validate radiographic measurements of range of motion of the knee after arthroplasty as part of a new system of virtual clinics. METHODS: The range of motion of 52 knees in 45 patients was obtained by 2 clinicians using standardised techniques and goniometers. Inter-rater reliability and intraclass correlation coefficients (ICCs) were calculated. Radiographs of these patients' knees in full active flexion and extension were also used to calculate intra and inter-rater reliability compared with clinical measurements using four different methods for plotting angles on the radiographs. RESULTS: The ICC for inter-rater reliability using the goniometer was very high. The ICC was 0.91 in extension and 0.85 in flexion while repeatability was 8.49° (-8.03-8.99°) in extension and 5.23° (-4.54-5.74°) in flexion. The best ICC for radiographic measurement in extension was 0.86, indicating 'near perfect' agreement, and repeatability was 5.43° (-4.04- 6.12°). The best ICC in flexion was 0.95 and repeatability was 5.82° (-3.38-6.55°). The ICC for intrarater reliability was 0.98 for extension and 0.99 for flexion on radiographic measurements. CONCLUSIONS: Validating the use of radiographs to reliably measure range of motion following knee arthroplasty has allowed us to set up a 'virtual knee clinic'. Combining validated questionnaires and radiographic measurement of range of motion, we aim to maintain high quality patient surveillance following knee arthroplasty, reduce our ratio for new to follow-up patients in line with Department of Health guidelines and improve patient satisfaction through reduced travel to hospital outpatients.

The measurement of patellar height: a review of the methods of imaging.

Many radiographic techniques have been described for measuring patellar height. They can be divided into two groups: those that relate the position of the patella to the femur (direct) and those that relate it to the tibia (indirect). This article looks at the methods that have been described, the logic behind their conception and the critical analyses that have been performed to test them.

Patellar height measurement in trochlear dysplasia.

A number of measurements of patellar height are in clinical use all of which reference from the tibia. The patellotrochlear index (PTI) has been proposed recently as a more accurate reflection of the functional height of the patella and described in normal knees. We compared patellar height measurements in patients with patellofemoral dysplasia. In a retrospective analysis of the MRI scans of 33 knees in 29 patients with patellofemoral dysplasia we assessed the inter- and intraobserver reliability of four patellar height measurements: the recently described PTI, Insall-Salvati (IS), Blackburne-Peel (BP) and Caton-Deschamps (CD) ratios. We also assessed the correlation between the different measurements in predicting patella alta. Three blinded observers on two separate occasions performed the measurements. There were 21 females and 8 males with a median age of 21 years (range 13-33). Statistical analysis revealed good inter-observer reliability for all measurements (0.78 for PTI, 0.78 for IS, 0.73 for BP and 0.77 for CD). Intra-observer reliability was also good (0.80, 0.83, 0.75 and 0.78, respectively). There was weak correlation between the PTI and the other ratios for patella alta. There was a strong correlation between the CD and BP ratios (0.96) and a moderate correlation between IS and CD and IS and BP ratios (0.594 and 0.539, respectively). We propose the PTI as a more clinically relevant measure than the IS, CD and BP ratios.

The management of patients with painful total knee replacement.

The management of patients with a painful total knee replacement requires careful assessment and a stepwise approach in order to diagnose the underlying pathology accurately. The management should include a multidisciplinary approach to the patient's pain as well as addressing the underlying aetiology. Pain should be treated with appropriate analgesia, according to the analgesic ladder of the World Health Organisation. Special measures should be taken to identify and to treat any neuropathic pain. There are a number of intrinsic and extrinsic causes of a painful knee replacement which should be identified and treated early. Patients with unexplained pain and without any recognised pathology should be treated conservatively since they may improve over a period of time and rarely do so after a revision operation.

Traumatic bone bruising--a review article.

The radiological assessment and classification of bone bruising are reviewed. Most of the literature relates to the knee and the effect of various injuries and their pattern of bone bruising is reviewed. The natural history of bone bruising and biochemical changes are also considered.

Evaluation of patients with a painful total knee replacement.

Evaluation of patients with painful total knee replacement requires a thorough clinical examination and relevant investigations in order to reach a diagnosis. Awareness of the common and uncommon problems leading to painful total knee replacement is useful in the diagnostic approach. This review article aims to act as a guide to the evaluation of patients with painful total knee replacement.

Late collapse of distal radius fractures after K-wire removal: is it significant?

BACKGROUND: The aim of this study was to find out whether distal radius fractures treated by Kirschner wire (K wire) fixation loose reduction after wire removal and analyze the variables may influence this. MATERIALS AND METHODS: Patients who underwent K wire fixation for unstable fractures of distal radius over a period of 3 years were included in this retrospective study. Fractures were classified according to AO classification. Radiographs taken just prior to removal of K wires and radiographs taken at least 1 month after wire removal were analyzed to study three radiological parameters; Palmar or dorsal tilt, radial inclination and ulnar variance. Loss of these angles was analyzed statistically against variables like age, sex, AO classification and duration of fixation. RESULTS: 59 fractures were analyzed with mean age of 56 years and male to female ratio of 1:2. Average loss of radial tilt was 2.6 degrees , loss of palmar tilt was 2.6 degrees and loss of ulnar variance was 1.3 mm. CONCLUSIONS: We found that distal radius fractures treated by percutaneous K wire fixation, did not suffer significant loss of reduction of fracture position after removal of wires. This remains true regardless of age, sex, fracture type according to AO type or duration of wire fixation.

Bone bruising of the knee.

Bone bruising demonstrated by MRI is discussed with histological findings and proposed classifications. The effects of the mechanism of injury on bone bruising at the knee and the natural history of the process are reviewed. The relationship of bone bruising to osteochondral sequelae and to osteoarthritis are considered.

Accessory ossicle or intraepiphyseal fracture of lateral malleolus: are we familiar with these?

A case of intraepiphyseal injury (type 7) to the lateral malleolus in a 11 year old child is described. This rare injury cannot be classified by commonly used Salter Harris classification for epiphyseal injury. Although less common, accessory ossicle of the malleoli is an important differential diagnosis for such injury. Details of type 7 intraepiphyseal injuries and accessory ossicle are described.