Long-term results of per-operative knee arthroscopy in confirming suitability for unicompartmental arthroplasty.

BACKGROUND: Patient selection is key to the success of medial unicondylar knee arthroplasty (UKA). Progression of arthritis is the most common indication for revision surgery. Per-operative arthroscopy is a means of directly assessing the integrity of the lateral compartment. The aim of the study is to assess the long-term survivorship of UKA performed when per-operative arthroscopy is used as a final means of deciding whether to proceed with UKA. METHODS: We used per-operative arthroscopy as a means to confirm suitability for UKA in a consecutive series of 279 Oxford medial UKA. Our series of UKA with per-operative arthroscopy (Group 1) was compared to all Oxford UKA (Group 2) and all UKA in the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) (Group 3). RESULTS: The 14-year cumulative percentage revision (CPR) was 18.5% (95% CI 12.7, 26.4) for group 1, 19.7% (95% CI 18.8, 20.6) for group 2, and 19.2% (95% CI 18.5, 19.8) for group 3. There was no statistically significant difference in the (CPR) for the entire period when group 1 was compared to groups 2 or 3. Progression of arthritis was least in Group 1 compared to groups 2 and 3; 3.6 versus 4.4 and 4.1% respectively. Following per-operative arthroscopy 21.6% (77/356) of knees underwent a change of surgical plan from UKA to TKA. CONCLUSION: In our practice, which includes per-operative arthroscopy, we have identified a reduced risk of revision due to progression of arthritis but no difference in overall long-term implant survivorship.

Editorial Commentary: Meniscus Message-What Is Possible or What Is Advisable?

Distal femoral varus osteotomy combined with meniscal allograft transplantation is a major surgical undertaking, not without risk and not to be taken on lightly by either the surgeon or the patient. It really is a salvage operation for a knee that is deteriorating and heading for arthroplasty at some future point. It is not an operation that should be offered to patients to allow them to return to sport. The fact that some patients do return to sport is good and is a credit to the operation and the patient's tenacity with rehabilitation, but we must question the rationale of such activity, which will most likely hasten the demise of the joint.

Effects of biomimetic surfaces and oxygen tension on redifferentiation of passaged human fibrochondrocytes in 2D and 3D cultures.

Due to its limited healing potential within the inner avascular region, functional repair of the meniscus remains a significant challenge in orthopaedic surgery. Tissue engineering of a meniscus implant using meniscal cells offers the promise of enhancing the reparative process and achieving functional meniscal repair. In this work, using quantitative real-time reverse transcriptase polymerase chain reaction (RT-qPCR) analysis, we show that human fibrochondrocytes rapidly dedifferentiate during monolayer expansion on standard tissue culture flasks, representing a significant limit to clinical use of this cell population for meniscal repair. Previously, we have characterized and described the feasibility of a tailored biomimetic surface (C6S surface) for reversing dedifferentiation of monolayer-expanded rat meniscal cells. The surface is comprised of major meniscal extracellular matrix (ECM) components in the inner region, namely collagen I/II (at a 2:3 ratio) and chondroitin-6-sulfate. We thus have further evaluated the effects of the C6S surface, alongside a number of other tailored surfaces, on cell adhesion, proliferation, matrix synthesis and relevant marker gene expression (collagen I, -II, aggrecan and Sox-9 etc) of passaged human fibrochondrocytes in 2D (coated glass coverslips) and 3D (surface-modified polymeric scaffolds) environments. We show that the C6S surface is permissive for cell adhesion, proliferation and ECM synthesis, as demonstrated using DNA quantification, 1,9-dimethylmethylene blue (DMMB) assay, histology and immunohistochemistry. More importantly, RT-qPCR analyses corroborate the feasibility of the C6S surface for reversing phenotypic changes, especially the downregulation of collagen II, of dedifferentiated human fibrochondrocytes. Furthermore, human fibrochondrocyte redifferentiation was enhanced by hypoxia in the 3D cultures, independent of hypoxia inducible factor (HIF) transcriptional activity and was shown to potentially involve the transcriptional activation of Sox-9.

Femoral nerve block vs fascia iliaca block for total knee arthroplasty postoperative pain control: a prospective, randomized controlled trial.

Femoral nerve block (FNB) is an accepted mode of analgesia for lower limb procedures but has a documented complication rate. This study compared femoral nerve and fascia iliaca regional anesthesia for total knee arthroplasty (TKA), using fentanyl consumption as the primary outcome measure. Ninety-eight primary unilateral TKA patients were blinded and randomized into fascia iliaca block (FIB) (n = 51) or FNB (n = 47) groups. No significant differences were found in analgesia use (fentanyl and tramadol) at 12 and 36 hours in pain, nausea and range of motion between the groups. There was one case of paresthesia in the femoral nerve in the FNB group. Fascia iliaca block is as effective as FNB as part of a multimodal anesthetic regimen for TKA.

Meniscus preservation; rationale, repair techniques and results.

It is inescapable that loss of part or all of the structure of the meniscus of the knee alters the biomechanics of knee function leading to a gradual deterioration of the chondral surface, which ultimately will result in osteoarthritis. The goal of the knee surgeon should therefore be to preserve as much as possible the function of the meniscus. Classic teaching is that many meniscal tears, which are peripheral and longtitudinal, will heal if sutured and protected during a slow healing process. However it is clear that other tear configurations can heal if given the opportunity by adequate preparation of the meniscus rim, careful suturing and delayed rehabilitation. Thus some radial tears, horn avulsions, double longtitudinal tears and retears, previously thought to be irreparable, can be sutured with good results. Over 12 years, 288 meniscus repairs were undertaken in 265 patients ranging in age from 12 to 70 years. Most were repaired at the time of anterior cruciate ligament reconstruction, although 55 were isolated repairs. While the average time from injury to surgery was 11.7 months (1 - 72), one third of patient's already had chondral damage of at least Outerbridge Grade 2. The purpose of this paper is to report on the more difficult meniscus repair techniques and as such formal follow up was not undertaken to determine the final outcome of these patients. Never the less it is estimated from known data that there was a retear rate in the order of less than 10%. There have been three complications, 2 infections and one temporary neuropraxia of the common peroneal nerve; all of these healed completely with appropriate treatment. Therefore we recommend that meniscus repair should be undertaken if a clinical case for meniscal preservation exists, even if the appearances are not those classically recommended.