Publications by authors named "Jan H Kuiper"

Objective: Traditional autologous chondrocyte implantation (ACI) involves arthroscopically harvesting a cartilage biopsy (stage 1), followed by arthrotomy 3 to 4 weeks later to apply a periosteal patch and implant culture-expanded chondrocytes underneath (stage 2). This study aimed to determine if patch application during stage 1 rather than stage 2 improved clinical outcome.

Design: A randomized controlled trial was conducted from 1998 to 2001.

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Purpose: To investigate patient demographic, injury and surgery/treatment-associated factors that can influence the patient-reported outcome (Lysholm score), following autologous chondrocyte implantation (ACI) in a large, 'real-world', nonuniform, prospective data examined retrospectively.

Methods: Knee patients treated at the Robert Jones and Agnes Hunt Orthopaedic Hospital, UK, using ACI between 1996 and 2020 were eligible. All longitudinal postoperative Lysholm scores collected between 1 and 23 years after ACI treatment and before any second major procedure (e.

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Treating bone-cartilage defects is a fundamental clinical problem. The ability of damaged cartilage to self-repair is limited due to its avascularity. Left untreated, these defects can lead to osteoarthritis.

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Background: Prophylactic antibiotics have significantly led to a reduction in the risk of post-operative surgical site infections (SSI) in orthopaedic surgery. The aim of using antibiotics for this purpose is to achieve serum and tissue drug levels that exceed, for the duration of the operation, the minimum inhibitory concentration of the likely organisms that are encountered. Prophylactic antibiotics reduce the rate of SSIs in lower limb arthroplasty from between 4% and 8% to between 1% and 3%.

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Aims: This study aims to report the medium term outcomes of circumferential periosteal release of the distal femur and distal tibia in treating paediatric leg length discrepancy (LLD).

Materials And Methods: A retrospective case series was performed on all patients undergoing circumferential periosteal release of the distal femur and/or tibia between 2006 and 2019. Data collected included demographics, surgical indications, post-operative leg lengths, and complications.

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Background: Treatment decisions for cartilage defects are often based on lesion size. Magnetic resonance imaging (MRI) is widely used to diagnose cartilage defects noninvasively; however, their size estimated from MRI may differ from defect sizes measured during arthrotomy, especially after debridement to healthy cartilage if undergoing autologous chondrocyte implantation.

Purpose/hypothesis: The purpose of this study was to evaluate the reliability of 2 methods to assess knee cartilage defect size on preoperative MRI and determine their accuracy in predicting postdebridement defect sizes recorded during arthrotomy.

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Background: Thicker (folded) facia lata autografts have been shown to be superior to thinner grafts and single-layered acellular human dermal (HD) allografts for superior capsular reconstruction (SCR) in biomechanical studies. The aim of this study was to evaluate the midterm clinical outcomes following SCR for irreparable supraspinatus tears using doubled (folded) HD allograft.

Methods: Thirty-two patients who had undergone SCR using doubled HD allograft between February 2012 and January 2020 were recruited in a continuous manner in this retrospective study.

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Purpose: The aims of this pilot randomised controlled trial (RCT) were to assess the safety and efficacy of a human dermal allograft patch and assess the feasibility of a future RCT comparing retear rate and functional outcome 12 months following standard and augmented double-row rotator cuff repair.

Methods:  A pilot RCT was conducted among patients undergoing arthroscopic repair of rotator cuff tear measuring between 1 and 5 cm. They were randomised to either augmented (double-row repair with human acellular dermal patch) or standard (double-row repair only).

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Background: Increased activity level is generally reported to be positively related to improved knee function after knee surgery. However, little research has been conducted into this relationship on an individual patient basis, or the influence of demographic and psychosocial factors such as patient affect-the subjective experience of emotion.

Hypothesis: The relationship between postoperative activity level and knee function will vary between patients and will be influenced by the patients' affect and demographic characteristics.

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Objective: To examine repair tissue formed approximately 15 months after a chondral harvest in the human knee.

Design: Sixteen individuals (12 males, 4 females, mean age 36 ± 9 years) underwent a chondral harvest in the trochlea as a pre-requisite for autologous chondrocyte implantation (ACI) treatment. The harvest site was assessed via MRI at 14.

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Background: There are limited randomized controlled trials with long-term outcomes comparing autologous chondrocyte implantation (ACI) versus alternative forms of surgical cartilage management within the knee.

Purpose: To determine at 5 years after surgery whether ACI was superior to alternative forms of cartilage management in patients after a failed previous treatment for chondral or osteochondral defects in the knee.

Study Design: Randomized controlled trial; Level of evidence, 1.

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Objective: The North Star Ambulatory Assessment (NSAA) is a validated 17-item functional rating scale and widely used to assess motor function in boys with Duchenne muscular dystrophy (DMD). The SARS-CoV-2 pandemic and subsequent Government 'lockdown' resulted in no face-to-face clinic visits hence the motor abilities were not monitored. The aim was to investigate whether the NSAA was feasible and reliable by video assessment.

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Osteochondral defects of the ankle (OCD) are being increasingly identified as a clinically significant consequence of injury to the ankle, with the potential to lead to osteoarthritis if left untreated. The aim of this retrospective cohort study was to evaluate a single-stage treatment of OCD, based on bone marrow aspirate (BMA) centrifuged to produce bone marrow concentrate (BMC). In a dual syringe, the concentrate was mixed with thrombin in one syringe, whereas hyaluronan and fibrinogen were mixed in a second syringe.

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Aims: The Oswestry-Bristol Classification (OBC) is an MRI-specific assessment tool to grade trochlear dysplasia. The aim of this study is to validate clinically the OBC by demonstrating its use in selecting treatments that are safe and effective.

Methods: The OBC and the patellotrochlear index were used as part of the Oswestry Patellotrochlear Algorithm (OPTA) to guide the surgical treatment of patients with patellar instability.

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Purpose: To investigate the effects of cross-education (CE) exercise on strength and performance at 10 and 24 weeks post anterior cruciate ligament (ACL) surgery.

Methods: Design: randomised controlled trial. N = 44 ACL-reconstruction patients, randomly-allocated into: CE: strength training of the non-operative limb, or CON: sham exercise of upper limb stretching.

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Article Synopsis
  • Research explores how communication between subchondral bone cells and transplanted chondrocytes affects cartilage repair, particularly comparing healthy versus degenerated bone.
  • An indirect co-culture model was created to study this interaction using human bone marrow-derived mesenchymal stem cells (BM-MSCs) from patients with varying degrees of osteoarthritis (OA) during knee surgery.
  • Findings indicate that late-stage OA BM-MSCs negatively impact chondrocyte function and matrix production, whereas early OA conditions promote healthier cartilage repair outcomes; highlighting the importance of subchondral bone health in cartilage repair strategies.
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Background: Hyperlipidemia is linked to poor tendon-to-bone healing and progression of fatty infiltration after rotator cuff repair. Statins effectively treat hyperlipidemia, but it is unknown if they have any potential detrimental effects following rotator cuff repair. The aim of this study was to evaluate the effect of statins on rotator cuff healing and fatty infiltration following repair.

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Articular cartilage is considered to have limited regenerative capacity, which has led to the search for therapies to limit or halt the progression of its destruction. Perlecan, a multifunctional heparan sulphate (HS) proteoglycan, promotes embryonic cartilage development and stabilises the mature tissue. We investigated the immunolocalisation of perlecan and collagen between donor-matched biopsies of human articular cartilage defects ( = 10 × 2) that were repaired either naturally or using autologous cell therapy, and with age-matched normal cartilage.

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Meniscus degeneration is closely related to the progression of knee osteoarthritis (OA). However, there is currently a lack of quantitative and objective metrics to assess OA meniscal cell phenotypes. In this study we investigated the phenotypic markers and chondrogenic potency of avascular and vascular meniscal cells and chondrocytes from medial OA knee joints (n = 10).

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It is well founded that the mechanical environment may regulate bone regeneration in orthopedic applications. The purpose of this study is to investigate the mechanical contributions of the scaffold and the host to bone regeneration, in terms of subject specificity, implantation site and sensitivity to the mechanical environment. Using a computational approach to model mechano-driven regeneration, bone ingrowth in porous titanium scaffolds was simulated in the distal femur and proximal tibia of three goats and compared to experimental results.

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Pulvertaft Weave (PTW) is an established method of tenorrhapy in tendon transfers. Previous studies have suggested that a Side-to-Side (STS) tenorrhapy is easier to perform has the same advantages and has greater load to failure, ultimate load and stiffness compared to PTW. However, there is insufficient data comparing behaviour of STS and PTW during cyclical loading.

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Article Synopsis
  • The study focuses on developing and validating the Soft Tissue Radiological Knee (SToRK) Index to quantify the soft tissue envelope around the knee, which can influence surgical procedures like total knee replacement.
  • Using weight-bearing radiographs and MRI to correlate soft tissue measurements, the SToRK Index showed a strong relationship with both the soft tissue cross-sectional areas and BMI, with notable differences between genders.
  • The findings suggest that the SToRK Index is a reliable and practical tool for surgeons, providing a clearer understanding of knee soft tissue distribution compared to traditional BMI measurements.
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Aims: We have previously demonstrated raised cobalt and chromium levels in patients with larger diameter femoral heads, following metal-on-polyethylene uncemented total hip arthroplasty. Further data have been collected, to see whether these associations have altered with time and to determine the long-term implications for these patients and our practice.

Methods: Patients from our previous study who underwent Trident-Accolade primary total hip arthroplasties using a metal-on-polyethylene bearing in 2009 were reviewed.

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Aims: Trochlear dysplasia is a significant risk factor for patellofemoral instability. The Dejour classification is currently considered the standard for classifying trochlear dysplasia, but numerous studies have reported poor reliability on both plain radiography and MRI. The severity of trochlear dysplasia is important to establish in order to guide surgical management.

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