Nicholas A. Smith

Validation of a New Technique to Determine Midbundle Femoral Tunnel Position in Anterior Cruciate Ligament Reconstruction Using 3-Dimensional Computed Tomography Analysis

PURPOSE The purpose of this study was to investigate and report on a new intraoperative measuring technique to place the anterior cruciate ligament (ACL) femoral tunnel in the center of the native ACL femoral insertion site. METHODS We investigated a novel measuring technique based on identifying the proximal border of the articular cartilage and using a specific ruler parallel to the femoral axis to locate the origin of the ACL. The accuracy of this technique was validated by measuring tunnel position on postoperative 3-dimensional computed tomography scans. Bony tunnels created by the ruler technique were compared with tunnels drilled by a traditional technique referenced from the back wall of the notch. RESULTS Fifty ACL reconstructions were performed by the novel measuring technique, with placement of the femoral tunnel at the center of the femoral insertion. The mean position for the center of the femoral tunnel measured by the ruler technique was 0.9 mm from the theoretic optimal center position but was a very distinct 5 mm from the mean position in the traditional tunnels. CONCLUSIONS The ruler technique produced femoral tunnels comparable to published radiographic criteria used for tunnel placement and is reproducible and accurate. We recommend placement of the femoral tunnel at the midpoint of the lateral femoral condyle when using the anatomic single-bundle technique. LEVEL OF EVIDENCE Level IV, case series.

A systematic review of the evidence for single stage and two stage revision of infected knee replacement

BackgroundPeriprosthetic infection about the knee is a devastating complication that may affect between 1% and 5% of knee replacement. With over 79 000 knee replacements being implanted each year in the UK, periprosthetic infection (PJI) is set to become an important burden of disease and cost to the healthcare economy. One of the important controversies in treatment of PJI is whether a single stage revision operation is superior to a two-stage procedure. This study sought to systematically evaluate the published evidence to determine which technique had lowest reinfection rates.MethodsA systematic review of the literature was undertaken using the MEDLINE and EMBASE databases with the aim to identify existing studies that present the outcomes of each surgical technique. Reinfection rate was the primary outcome measure. Studies of specific subsets of patients such as resistant organisms were excluded.Results63 studies were identified that met the inclusion criteria. The majority of which (58) were reports of two-stage revision. Reinfection rated varied between 0% and 41% in two-stage studies, and 0% and 11% in single stage studies. No clinical trials were identified and the majority of studies were observational studies.ConclusionsEvidence for both one-stage and two-stage revision is largely of low quality. The evidence basis for two-stage revision is significantly larger, and further work into direct comparison between the two techniques should be undertaken as a priority.

Meniscal allograft transplantation: rationale for treatment.

The anatomy and microstructure of the menisci allow the effective distribution of load across the knee. Meniscectomy alters the biomechanical environment and is a potent risk factor for osteoarthritis. Despite a trend towards meniscus-preserving surgery, many tears are irreparable, and many repairs fail. Meniscal allograft transplantation has principally been carried out for pain in patients who have had a meniscectomy. Numerous case series have reported a significant improvement in patient-reported outcomes after surgery, but randomised controlled trials have not been undertaken. It is scientifically plausible that meniscal allograft transplantation is protective of cartilage, but this has not been established clinically to date.

Systematic review of microendoscopic discectomy for lumbar disc herniation

Study designSystematic review.ObjectiveTo search and analyse randomised controlled trials (RCTs) published since the Cochrane review by Gibson and Waddell (2007) comparing microendoscopic discectomy (MED) with open discectomy (OD) or microdiscectomy (MD) and to assess whether MED improves patient-reported outcomes.Summary of backgroundDiscectomy for symptomatic herniated lumbar discs is an effective operative treatment. A number of operative techniques exist including OD, MD, and MED. A 2007 Cochrane review identified OD as an effective treatment for symptom improvement, and found sufficient evidence for MD. However, evidence for MED was lacking.MethodsA systematic review of Medline and Embase was carried out. Aiming to identify RCTs carried out after 2007, which compared OD with MD and MED which reported the Oswestry disability index (ODI) as an outcome.ResultsFour RCTs were identified. None of the studies found a significant difference in the ODI scores between study groups at any time point. Three studies compared MED to OD and one compared OD, MD, and MED. The largest study reported an increased number of severe complications in the MED group.ConclusionsThere is some evidence to suggest that MED performed by surgeons skilled in the technique in tertiary referral centres is as effective as OD.

Enhanced education and physiotherapy before knee replacement; is it worth it? A systematic review.

BACKGROUND Around 20% of knee replacement have an unsatisfactory outcome. Pre-operative physiotherapy and education have been proposed to improve post-operative outcomes. OBJECTIVES This systematic review evaluated whether these factors improved length of stay and patient reported outcomes after knee replacement surgery. DATA SOURCES Medline, Embase, CINAHL, Cochrane Central Register of Controlled Trials, PsycINFO and PEDro were searched on the 1st January 2013. STUDY SELECTION OR ELIGIBILITY CRITERIA Randomised or quasi-randomised studies assessing either pre-operative education or physiotherapy on patients undergoing a planned total or partial knee replacement were included in the review. Only studies with a control group receiving a defined standard of pre-operative care were included. RESULTS Eleven studies met the inclusion criteria set. Two studies analysed the effect of pre-operative education, seven pre-operative treatment by a physiotherapist and two studies used both factors. No study found significant differences in validated joint specific patient reported outcome measures. The education studies found a decrease in pre-operative expectation and an improvement in knowledge, flexion and regularity of exercise. Two studies found an improvement in muscle strength in the group treated by a physiotherapist at three months. The combination of education and physiotherapy was shown to reduce patient length of stay and cost in one study. CONCLUSION The evidence reviewed is insufficient to support the implementation of either pre-operative education or physiotherapy programmes. The combination of pre-operative education and treatment by a physiotherapist may reduce the medical costs associated with surgery.

Factors Predicting Meniscal Allograft Transplantation Failure.

Background: Meniscal allograft transplantation (MAT) is performed to improve symptoms and function in patients with a meniscal-deficient compartment of the knee. Numerous studies have shown a consistent improvement in patient-reported outcomes, but high failure rates have been reported by some studies. The typical patients undergoing MAT often have multiple other pathologies that require treatment at the time of surgery. The factors that predict failure of a meniscal allograft within this complex patient group are not clearly defined. Purpose: To determine predictors of MAT failure in a large series to refine the indications for surgery and better inform future patients. Study Design: Cohort study; Level of evidence, 3. Methods: All patients undergoing MAT at a single institution between May 2005 and May 2014 with a minimum of 1-year follow-up were prospectively evaluated and included in this study. Failure was defined as removal of the allograft, revision transplantation, or conversion to a joint replacement. Patients were grouped according to the articular cartilage status at the time of the index surgery: group 1, intact or partial-thickness chondral loss; group 2, full-thickness chondral loss 1 condyle; and group 3, full-thickness chondral loss both condyles. The Cox proportional hazards model was used to determine significant predictors of failure, independently of other factors. Kaplan-Meier survival curves were produced for overall survival and significant predictors of failure in the Cox proportional hazards model. Results: There were 125 consecutive MATs performed, with 1 patient lost to follow-up. The median follow-up was 3 years (range, 1-10 years). The 5-year graft survival for the entire cohort was 82% (group 1, 97%; group 2, 82%; group 3, 62%). The probability of failure in group 1 was 85% lower (95% CI, 13%-97%) than in group 3 at any time. The probability of failure with lateral allografts was 76% lower (95% CI, 16%-89%) than medial allografts at any time. Conclusion: This study showed that the presence of severe cartilage damage at the time of MAT and medial allografts were significantly predictive of failure. Surgeons and patients should use this information when considering the risks and benefits of surgery.

Meniscal Transplantation and its Effect on Osteoarthritis Risk: an abridged protocol for the MeTEOR study: a comprehensive cohort study incorporating a pilot randomised controlled trial

Objectives Subtotal or total meniscectomy in the medial or lateral compartment of the knee results in a high risk of future osteoarthritis. Meniscal allograft transplantation has been performed for over thirty years with the scientifically plausible hypothesis that it functions in a similar way to a native meniscus. It is thought that a meniscal allograft transplant has a chondroprotective effect, reducing symptoms and the long-term risk of osteoarthritis. However, this hypothesis has never been tested in a high-quality study on human participants. This study aims to address this shortfall by performing a pilot randomised controlled trial within the context of a comprehensive cohort study design. Methods Patients will be randomised to receive either meniscal transplant or a non-operative, personalised knee therapy program. MRIs will be performed every four months for one year. The primary endpoint is the mean change in cartilage volume in the weight-bearing area of the knee at one year post intervention. Secondary outcome measures include the mean change in cartilage thickness, T2 maps, patient-reported outcome measures, health economics assessment and complications. Results This study is expected to report its findings in 2016. Cite this article: Bone Joint Res 2015;4:93–8

Arthroscopic Meniscal Allograft Transplantation With Soft-Tissue Fixation Through Bone Tunnels

Meniscal allograft transplantation improves clinical outcomes for patients with symptomatic meniscus-deficient knees. We describe an established arthroscopic technique for meniscal allograft transplantation without the need for bone fixation of the meniscal horns. After preparation of the meniscal bed, the meniscus is parachuted into the knee through a silicone cannula and the meniscal horns are fixed with sutures through bone tunnels. The body of the meniscus is then fixed with a combination of all-inside and inside-out sutures. This technique is reliable and reproducible and has clinical outcomes comparable with those of bone plug fixation techniques.

A case series of 35 hip revisions for adverse reactions to metal debris following cormet hip resurfacing

The primary aim of this study was to analyse our painful metal-on-metal (MoM) hip resurfacing revisions with evidence of ‘adverse reactions to metal debris’ (ARMD). In our series of 35 revisions the median whole blood Cobalt levels were 58 nmols/l (range 12-1407 nmols/l), and whole blood Chromium levels were 73 nmols/l (range 2-353 nmols/l). Thirty-four of our 35 patients had abnormal imaging on Ultrasound scanning (USS). The mean histological Campbell grading of ARMD was 4, and ranged from 0-9. The mean Oxford Hip Score (OHS) increased from 19 pre-revision (range 4-46) to 33 post-revision surgery (range 23-47). We found no correlation between the preoperative metal ion levels, and the severity of the disease or the outcome. Pain following hip resurfacing may arise from a number of causes and when groin pain arises in conjunction with abnormal cross sectional imaging we have offered our patients revision surgery regardless of raised metal ions or grossly abnormal imaging, with good results.

Sensitivities, Specificities, and Predictive Values of Microbiological Culture Techniques for the Diagnosis of Prosthetic Joint Infection

Background. Identifying the microorganism in a prosthetic joint infection is the key to appropriately targeting antimicrobial treatment. Despite the availability of various techniques, no single test is considered the definitive gold standard. Aim. Our aim was to determine the sensitivity, specificity, and positive/negative predictive values for a variety of culture techniques. Methods. We performed a retrospective case series of 219 patients undergoing revision surgery of their hip or knee replacement between May 2004 and February 2013. The patients were classified as either infected or noninfected according to criteria set out by the Musculoskeletal Infection Society. The number and type of samples taken intraoperatively varied between cases but included tissue samples and fluid sent in either blood culture vials or sterile containers. Results. The highest sensitivity was found with blood culture vials (0.85) compared to fluid in sterile containers (0.26) and tissues samples (0.32). Blood culture vials also had a better specificity and positive and negative predictive values profile. Conclusion. We conclude that, of the techniques studied, fluid in blood culture vials had the best profile for the correct identification of microorganisms and advocate its use.